Description : A car moving with a speed of 40 km/h can be stopped by applying brakes after at least 2m. If the same car is moving with a speed of 80 km/h., what is
Last Answer : A car moving with a speed of 40 km/h can be stopped by applying brakes after at least 2m. If the same car is moving ... A. 2 m B. 4 m C. 6 m D. 8 m
Description : A car moving along a straight road with a speed of 120 km/hr, is brought to rest by applying brakes.
Last Answer : A car moving along a straight road with a speed of 120 km/hr, is brought to rest by applying brakes. ... (ii) time taken by the car to come to rest.
Description : Stopping distance of vehicles : When brakes are applied to a moving vehicle, the distance it travels before stopping is called stopping distance. It is an important factor for road safety and depends on ... the brake with the deceleration of 5m/s2. Find the stopping distance of the car -Science
Last Answer : Here u=72 km/hr = 72×10003600m/s=2072×10003600m/s=20 m/s , v=0 a= -5 m/s2 Now using the relation v2=u2+2asv2=u2+2as 0=(20)2+2×(−5)×s0=(20)2+2×(−5)×s s=40ms=40m
Description : A goodstrain of 700 m runs at a speed of 165 km/hr. A person traveling in it observes that the mail train moving in opposite direction takes 30 seconds to cross him. Find the speed of the mail train, if it is 750 m long. A) 8.4 m/s B) 5.3 m/s C) 2.5 m/s D) 6.8 m/s
Last Answer : ANSWER:C Explanation: Speed of goods train = 165km/hr length of mail train (P) = 750m length of goods train (Q) = 700m Alternately, we can directly use the formula: Time = ( p+q) / (v1+v2) sec ( ... 45.833+v2 = 48.333 V2 = 2.5 m/s Therefore the speed of the mail train is 2.5 m/s
Description : A passenger train 165 m long which is running at a speed of 30km/hr. In what time will it pass a man who is running at a speed of 3 km/hr in the opposite direction. In which the train is moving. A)14 sec B) 17sec C)16sec D)18sec
Last Answer : ANSWER: D Explanation: Speed of the train = 30 km/hr Speed of man = 3 km/hr Length of the train = 165m If direction is given in opposite direction then we add both speed. That is (30 + 3 )= 33 km/hr ... can easily get the distance of m/s So it cover 165 m i.e., 165 * 6 /55 = 18 sec.
Description : A body of mass `(1)/(4) kg` moving with velocity `12 m//s` is stopped by applying a force of 0.6 N. Then impulse is :-
Last Answer : A body of mass `(1)/(4) kg` moving with velocity `12 m//s` is stopped by applying a force of 0.6 N. Then ... A. 7.2 Ns B. 3 Ns C. 2.4 Ns D. None
Description : Ravi walks to and fro to a Gym. He spends 30 minutes in gym. If he walks at speed of 20 km an hour, he returns to home at 8.00 a.m. If he walks at 30 km an hour, he returns to home at 7.30 a.m. How fast must he walk in order to return at 7.15 hours? a) 40 km/hr b) 30 km/hr c) 60 km/hr d) 50 km/hr
Last Answer : A As per the question, let D be the total distance and ‘t’ is the time taken. So we have: D=20t 20t =30(t-0.5) 20t=30t-15 10t=15 t=3/2 D= 30 km Now, for the condition given we have: 30=S(t-3/4) 30=S(3/2-3/4) 30=S((6-3)/4) 30=S(3/4) S=40 km/hr
Description : A train 170 m long is running at a speed of 22.5 km/hr. what time will it take to cross a 80m long bridge? A) 20 sec B) 40 sec C) 15 sec D) 30sec
Last Answer : ANSWER:B Explanation: Length of the train = 170 m Length of the bridge = 80 m Therefore, length of the train + length of the bridge = (170 + 80) m = 250m Speed of the train = 22.5 km/hr Speed ... .25m/sec Therefore, time taken by the train to cross the bridge = 250 m/6.25 m/sec. = 40 seconds.
Description : A car moves at a constant speed of 60 km/hr for 1 km and 40 km/hr for next 1 km. What is the average speed of the car?
Last Answer : A car moves at a constant speed of 60 km/hr for 1 km and 40 km/hr for next 1 km. What is the average speed of the car?
Description : Anitha travels 400 km by bus at 70 km/hr, 600 km by train at 80km/hr, 250 km by bike at 60 km/hr and 50 kn by car at 40 km/hr. what is the average speed for the total distance? a) 68.45 b) 69.45 c) 67.45 d) 69.77
Last Answer : D Total distance = (400+250+50+600)km =1300 km Total time taken = (400/70 + 600/80+250/60+50/40) hrs =(40/7 +60/8+25/6+5/4) =(24*40)+(21*60)+(28*25)+(42*5) / 168 =960+1260+700+210 / 168 =(3130 / 168) Average speed =(1300*168 / 3130) km/hr =218400/3130 =69.77 km/hr
Description : A girl covered a definite distance at same speed. Had she moved 6 km/hr faster, she would have taken 30 mins less. If she had moved 4 km/hr slower, she would have taken 30 mins more. The distance (in km) is. a) 50 b) 40 c) 70 d) 60
Last Answer : D Let distance = x km Rate = y km/hr x/y - x / (y+6) = 30/60 (x(y+6)-xy) / y(y+6) = ½ (xy +6x - xy) / y(y+6) = ½ 12x = y(y+6) ------------>1 And x/ (y-4) - x/y = 30/60 (Xy - x(y-4 ... = (y+6) / (y-4) 3y - 12 = 2y +12 Y = 24km Put y value in 1 we get 12x = 24 (24+6) 12x = 24 *30 X=60km
Description : Minimum stopping distance for moving vehicles on road with a design speed of 80 km/hour, is (A) 80 m (B) 100 m (C) 120 m (D) 150 m
Last Answer : Answer: Option C
Description : Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is: A.40 m B.55 m C.65 m D.50 m E.None of these
Last Answer : Answer- D (50) Explanation – Relative speed= total lengths/time (46-36) x 5/18 = [L + L ] / 36 10 x (5/18) x36 x (1/2)= L L=50 m
Description : Two trains are running at 40 km/hr and 20 km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 5 seconds. What is the length of the fast train? A.27 7/9 m B.28 m C.29 m D.30 2/7 m E.None of these
Last Answer : Answer – A (27 7/9 m) Explanation – When SAME direction- MINUS Relative speed = (40-20) km/hr = [20 x 5/18] m/sec = [50/9] m/sec. Length of faster train = sxt=[50/9 x 5] m = 250/9 m = 27 7/9 m.
Description : A 250 m goods train takes 50 s to cross a person who is going in the same direction with the speed of 8 km/h. After crossing that person, the train can reach next station in 2 hr. How long that person takes to reach that station after being crossed by them? A) 2 ½ hr B) 5hr C) 3 1/2hr D) 1hr
Last Answer : ANSWER:A Explanation: Speed of the person = 8 kmph = (8*5/18)m/s = 20/9 m/s Then relative speed of train = (x-20/9)m/s As train takes 50 sec to cross the person Therefore 50 =250/(x-20/ ... 20,000 m = 20 km Thus time taken by the person to cover the distance of 20km= 20/8 hr=2 ½ hr
Description : A train travels between two stations 15 km apart in 18 minutes. If the train accelerates for a part of journey uniformly followed by uniform retardation, the maximum speed attained by the train during the journey will by a.125 km/hr b.107 dynes c.80 km/hr d.100 km/hr e.60 km/hr
Last Answer : d. 100 km/hr
Description : A train travels between two stations 15 km, apart in 18 minutes. If the train accelerates for a part of journey uniformly followed by uniform relardation, the maximum speed attained by the train, during, the journey, will be a.60 km/hr b.80 km/hr c.125 km/hr d.100 km/hr e.107 dynes
Description : A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is: a) 35.55 km/hr b) 36 km/hr c) 71.11 km/hr d) 71 km/hr e) 69.69km/hr
Last Answer : Total time taken = (160/64) + (160/80) = 9/2 hrs. Avg Speed – 320 × (2/9) km/hr = 71.11km/hr Answer: c)
Description : A passenger train without stopping running at an average speed of 120 km/hr and with stoppages at an average speed of 80 km/hr. What is the total time taken by the train for stoppages on a route of length 480km? a) 2 hours b) 3 hours c) 4 hours d) 5 hours
Last Answer : A Let r = running time of the train s= stoppage time of the train D= total distance travelled by train We have: D/r= 120 and ..(1) D/(r+s) =80 ..(2) Diviving (1)&(2), D/r *(r+s)/D = ... , D=480 kms 480/r= 120 r=4 put r value in (3),we get s/4 =1/2 S = 2 hours
Description : A motorboat can cover 80 km upstream and 120 km downstream together in 26 hours. Also it can cover 100 km upstream and 144 km downstream together in 32 hours. What is the speed of the motorboat in still water? A) 12 km/hr B) 15km/hr C) 8.5km/hr D) 19km/hr
Last Answer : ANSWER :C Explanation: Upstream speed in both cases is 80 and 100. Ratio is 80 : 100 = 8:10 = 4 : 5. So let times in both cases be 4x and 5x Downstream speed in both cases is 120 and 144 resp. Ratio is ... 12 km/hr So speed of boat = 1/2 * (5+12) =17/2km/hr speed of boat = 8.5 km/hr
Description : Two trains, both 50m long, moving in opposite directions cross each other in 4 seconds. If one is moving thrice as fast the other, then the speed of the faster train is. A) 45km/hr B) 19 km/hr C) 95 km/hr D) 67.5 km/hr
Last Answer : ANSWER:D Explanation: Let the speed of the slower train be x' m/sec The speed of the sfaster train = 3x m/s Relative speed = (x +3x)m/sec = 4x m/sec 50 + 50 / 4 = 4x 100 / 4 = 4x 100 = 16x x = 100 ... the faster train = 3 * 25 / 4 = 75 / 4 m/s = (75/4 *18 /5)km/hr = 67.5 km/hr
Description : A train 135m long is moving at a speed of 12.5 km/h. It will cross a girl coming from the opposite direction at a speed of 1km/hr in. A) 36sec B) 46sec C) 56sec D) 66sec
Last Answer : ANSWER : A Explanation: Speed of the train = 12.5 km/hr Speed of girl = 1 km/hr Relative speed = speed of train + speed of girl = (12.5 + 1) km/hr = 13.5 km/hr Convert km/hr into m/s 13.5 ... .75 m/s Time = distance / speed Time taken by the train to pass the man = 135 / 3.75 = 36 sec.
Description : A passenger train 300m long is running with a speed of 136 km/hr. In what time will it pass a boy who is running at 6 km/hr in opposite direction in which the train is moving? A) 8.6sec B) 7.6sec C) 3.6sec D) 2.6sec
Last Answer : ANSWER: B Explanation: Speed of the train = 136 km/hr Speed of boy = 6 km/hr Speed of the train relative to boy = (13 + 6)km/hr = 142 km/hr Convert km/hr into m/s 142 km /hr = (142 * 5 / 18 ... taken bt it to cover 300 m at 39.44 m/s =300 / 39.44 [speed time= distance / speed] = 7.6 sec
Description : A train 100 m long is moving with the velocity of 72 km/hr. Find the time it takes to cross the bridge which is 2 km long? -Science
Last Answer : Given Lenght of Train = 100m , velocity = 72 km/hr = 20 m/s, Lenght of the Bridge =2 Km. Total distance covered by the train to fully pass the bridge = 2000 + 100 = 2100 m So, time taken time=distancevelocity=210020=105sectime=distancevelocity=210020=105sec
Description : A car travelling at a speed of 60 km/hour is braked and comes to rest 6 seconds after the brakes are applied. The minimum coefficient of driction between the wheels and the road would be a.0.107 b.0.3 c.0.283 d.0.417 e.0.5
Last Answer : c. 0.283
Description : A train 125 m long passes a man, running at 5 kmph in the same direction in which the train is going, in 10 seconds. The speed of the train is: A.35 km/hr B.50 km/hr C.48 km/hr D.55 km/hr E.None of these
Last Answer : Answer – B (50 km/hr) Explanation – Let speed be S Relative speed = total lengths/time [ in this case man length is neglible compare to train so neglected] (S – 5) x 5/18 = 125 /10 S- 5 = (125/10)x(18/5) S-5 = 45 S=50 km/hr
Description : If Gowtham ride a bike at 30 km/hr, then he arrives at a certain place at 3 p.m. If he ride at 45 km/hr, he will arrive at the same place at 1 P.m. At what speed must he ride to get there at noon? a) 18 km/hr b) 24 km/hr c) 36 km/hr d) 28 km/hr
Last Answer : C When speed of gowtham = 30 km/hr =d/t and, When speed of the gowtham = 45 km/hr =d/(t−2) Equating the value of d: 30t =45(t-2) 30t=45t-90 15t=90 t=6 hours Finally desired speed =d/(t-1) =30t/(t-1) =30*6/(6-1) =180/5 =36 km/hr
Description : A train M speeding with 60km/hr crooses another train N, running in the same direction in 1 min. If the lengths of the trains M and N be 50m and 100m respectively. What is the speed of train N? A) 15 km/hr B) 61km/hr C) 51km/hr D) 50k/hr
Last Answer : ANSWER: C Explanation: Let the speed of be train N be ‘x’km/hr Speed of M relative to N = (60 – x)km/hr = (60-x) * 5/18]m/s = (300 – 5x / 18)m/s 150 / (300 – 5x / 18) =60 2700/300-5x=60 2700=18000-300x 300x=15300 x= 153/3 x=51km/hr Therefore the speed of the train is 51 km/hr
Description : A train overtakes two girls walking along a railway track. The first girl walks at 9 km/hr. The other girl walks at 10.8 km/hr. The train needs 16.8 and 17 seconds respectively to overtake them. What is the speed of the ... in the same direction as the train? A) 25 m/s B) 45 m/s C) 30m/s D) 40m/s
Last Answer : ANSWER:B Explanation: First girl speed = 9km/hr = 9 * 5 / 18 m/s = 5/2 m/s = 2.5 m/s second girl speed = 10.8 km/hr = 10.8 * 5/18 m/s = 54/18 = 3 m/s Let the speed of the train ... x - 3) * 17 16.8x - 42 = 17x - 51 0.2x = 9 x = 45 Therefore the speed of the train is 45 m/s
Description : A person runs on the platform of 90 m at a speed of 5km/hr in the same direction of the passenger train. Find the time taken by the train to cross the running person if speed of the train is 35.5 km/hr? (Length of train = Length of platform) A) 5.32sec B) 7.5sec C) 12.6sec D) 10.62sec
Last Answer : ANSWER:D Explanation: speed of the train = 35.5 km/hr speed of the person = 5 km/hr As the train and the running person move in same direction, their speed values are subtracted to find the relative ... =10.62 sec Hence, the time taken by the train to cross the running person is 10.62 sec
Description : A girl is walking at a speed of 15 km/hr along a railway track. If she is 600 m ahead of the train which is 300 m long and runs at a speed of 180 km/hr in same direction, then what is the time required to pass a girl? A) 19.63sec B) 32sec C) 8.2sec D) 28.3sec
Last Answer : ANSWER:A Explanation: Speed of a girl = 15 km/hr speed of train = 180 km/hr By using the condition, The speed values of train and the moving object are subtracted if they are moving in same ... /45.83 = 19.63 Hence the time taken by the train to cross the girl is 19.63seconds
Description : A boat goes 30 km upstream and 44 km downstream in 10 hours. In 13 hours it can go 40 km upstream and 55 km downstream. Then what is the speed of the stream? (a) 3km/hr (b) 5km/hr (c) 6km/hr (d) 7km/hr
Last Answer : (a) 3km/hr
Description : A bus starts at bus stop and reaches a destination in 4 hours. If it travels first and second half at the speed of 40 km/hr and 50 km/hr respectively then the distance between bus stop and destination is a) 177.7 km b) 154.2 km c) 163.5 km d) 147.3 km
Last Answer : A Let the distance between bus stop and destination be X. The total time taken by the bus to cover X = 4 hours Since X/2 by 40km/hr and remaining X/2 by 50km/hr Then by Time = distance/speed, we have ... = 1600 9X = 1600 X = 1600/9 = 177.7 Hence 177.7 km is the required answer.
Description : Raghu starts a bike at 40 km/hr and he increases his speed in every hour by 4 km/hr. Then the maximum distance covered by him in 12 hours is: a) 744 km b) 658 km c) 436 km d) 512 km
Last Answer : A Speed of the rider = 40km/hr. Distance covered in 1st hour = 40 km. He increased his speed in every 1 hour by 4 km/hr. Distance covered in every 1 hours will be, 44, 48, ,... upto 12 terms.(for 12 hours). ... (2(40)+(11)4) = 6(80 + 44) = 6(124) = 744. Hence, he covers 744 km in 12 hours.
Description : A taxi driver make a trip from the plains to ooty which are 340km apart at an average speed of 60km/hr. In the return trip, he covers the speed distance at an average of 30 km/hr. the average speed of the taxi over the entire distance of 680 km is a) 30 b) 40 c) 50 d) 60
Last Answer : B Average speed =(2xy/( x+y)) km/hr Given x =60 km/hr y = 30km/hr Average speed = (2*60*30/ (60+30)) km/hr =(3600/ 90) =40 km/hr
Description : Tharun has to cover a distance of 84 km in 40 minutes. If he covers one-half of the distance in one-fourth of the total time, to cover the remaining distance in the remaining time, what should be his speed in km/hr? a) 42 km/hr b) 64km/hr c) 84km/hr d)76km/hr
Last Answer : C Tharun needs to cover 84 km in 40minutes Given that he covers one-half of the distance in one-fourth of the total time ⇒ he covers half of 84km in one-fourth of 40 minutes ⇒ He covers 42 km in ¼ * ... Distance =42km Time =30minutes =1/2 hr Required Speed = Distance / Time =42/(1/2)=84 km/hr
Description : 1/2of a certain travel is covered at the rate of 30km/hr, one-third at the rate of 40 km/hr and the rest at 35km/hr. Find the average speed for the whole travel. A) 33 1/3 B) 33 3/5 C) 34 3/7 D) None of these
Last Answer : B) let the total travel be X km. Then X/2 km at the speed of 30 km/hr and X/3 km at 40 km/hr and the rest distance( X - X/2 - X/3) =1/6 X at the speed of 35km/hr. Total time taken during the travel ... 2*30 hrs+ X/3*40hrs+ X/6*35hrs = 5X/168 hrs Average speed =X/(5x/168) = 168/5 =33 3/5km hr
Description : A certain thing is thrown twice from a place with the gap of 45 minutes between the two shots. A girl approaching this point in a train heard the second shot 44 minutes after she heard the first shot. What is the speed of train ... travels at 660 m/s? a) 62 km/hr b) 54 km/hr c) 48 km/hr d) 27 km/hr
Last Answer : B Actual time between the two shots being fired = 45 minutes. If a girl was stationary she would have heard the shots after 44 minutes. But since the train was moving towards the source, she heard the second shot after ... = (15 *18/5) km/hr =54 km/hr Hence the speed of the train is 54 km/hr
Description : A bike starts with a speed of 60 km/hr at 8a.m. Due to the problem in engine it reduces its speed as 20 km/hr for every 1 hour. After 9 am, the time taken to covers 15 km is: a) 13 minutes and 20 seconds b) 15 minutes and 09 seconds c) 18 minutes and 15 seconds d) 22 minutes and 30 seconds
Last Answer : 15 min
Description : Senthil started bike at 5 a.m to reach a temple. After going temple, his bike went out of order. Consequently he rested for 45 mins and came back to his house walking all the way. Senthil reached home at 8 a.m. if bike ... /hr, then on bike he covered a distance of. a) 3.12 b) 2.76 c) 4.13 d) 2.14
Last Answer : D Time taken = 2 hr 15 mins = 2 ¼ hrs Time = 9/4 hrs Let the required distance be x km Then x/20 + x/1 = 9/4 (X+20x) / 20 = 9/4 21x / 20 = 9/4 84x = 180 X= 2.14 km Therefore the required diatance is 2.14 km
Description : Two mail trains Pand Q of 300 m and 600m, run at speed of 130 km/hr and 160 km/hr respectively, in the direction opposite direction to each other. Find the time required to cross each other after the moment they met? A) 11.17 sec B) 12sec C) 9.10sec D) 21sec
Last Answer : ANSWER:A Explanation: Length of train P = 300 m Length of train Q = 600 m Speed of train p = 130 kmph Convert km/hr into m/s, Speed of train p =(130 *5/18)m/s = 650/18 m/s = 36.11 m/ ... train B) = (300+600)m = 900 m We know, time =distance /speed = 900/ 80.55 = 11.17seconds
Description : A car is travelling at 90 km/hour on a rough road where the coefficient of friction between the road and the tyre is 0.5. The distance the car will skid before stopping when the brakes are jammed suddenly would be a.127.4 m b.95.55 m c.63.7 m d.31.85 m e.90 m
Last Answer : c. 63.7 m
Description : For a vehicle moving with a speed of 80 km per hour, the brake reaction time, in ordinary cases, is (A) 1 sec (B) 1.5 sec (C) 2.0 sec (D) 2.5 sec
Last Answer : Answer: Option D
Description : Ganesh is travelling on his motorbike and has calculated to reach golden temple at 8 p.m if he travels at 30 km/hr; he will reach there at 6 p.m if he travels at 45 km/hr. At what speed must he travel to reach the golden temple at 7 p.m? a) 36 b) 46 c) 32 d) 30
Last Answer : A Let the distance travelled be x km x/30 – x/45 = 2 (3x – 2x) / 90 = 2 x/90 = 2 x = 180km Time taken to travel 180 km at 30 km/hr = 180 / 30 = 6 hrs So ganesh started 6 hrs before 8 pm That is 2 pm Required speed = distance / time =(180/5) =36 km/hr
Description : A train 330 m long passes a man, running at 18 km/hr in the direction opposite to that of the train in 18 seconds. The speed of the train is. A) 38 km/hr B) 29km/hr C) 48km/hr D) 44km/hr
Last Answer : ANSWER: C Explanation: Length of the train = 330 m Speed = distance / time. Speed of the train relative to man = 330 / 18 m/s = 110 / 6 m/s Convert m/s into km/hr Therefore 110 / 6 m/s = (110 / ... (x +18) = 66 km/hr X + 18 = 66 X = 48 Therefore the speed of the train is 48 km/hr.
Description : A boy sitting in a train which is travelling at 25 km/hr observes that a goods train travelling in opposite direction, takes 4.5 seconds to pass him. If the train is 140 m long, find its speed. A) 77km/hr B) 79km/hr C) 87km/hr D) 89km/hr
Last Answer : ANSWER : C Explanation: Relative speed = distance / time = (140 / 4.5) m/s = 31.11 m/s Convert m/s into km/hr 31.11 m/s = (31.11 * 18 / 50 km/hr = (560 / 5) km/hr = ... train (by sitting) = (112 - 25) km/hr = 87 km/hr Therefore the speed of goods train is 87 km/hr.
Description : A mail train 220 m long is running with a sped of 120 km/hr. What is the time in which it will pass a man who starts from the engine running at the speed of 12km/hr in the direction opposite to that of the train. A) 6sec B) 5sec C) 4sec D) 3sec
Last Answer : ANSWER: A Explanation: We know as the train and the running person are moving in opposite direction,therir speed values are added to find the relative speed. Relative speed = speed of mail train + speed of running ... [ from the length of the mail train is the distance] = 220 / 36.66 = 6 sec.
Description : A train crosses a platform and a scooter standing on the platform in 20 seconds, 12seconds respectively.What is the length of the platform if the speed of the train is 25 km/hr? A) 55.8 m B) 75m C) 124m D) 68.5m
Last Answer : Answer: A Explanation: Given that, The speed of the train = 25km/hr = 25x 5/18 m/sec = 125/18 m/sec The train crosses a scooter in 12 seconds. Then, Length of the train = 125/18*12= 83.33 Now, ... 18(X +83.3)= 2500 18X=1000.6 X=55.58 m Hence the platform is 55.58 m long.
Description : A train 560 m long crosses the platform of length 340 m in 45seconds. Find the speed of the train in km/hr A) 72km/hr B) 36km/hr C) 48km/hr D) 15km/hr
Last Answer : ANSWER:A Explanation: Length of the train = 560 m Length of the platform = 340 m Therefore, length of the train + length of the platform = 560 m + 340 m = 900 m Time taken by the train to cross the ... to km/hr, multiply by 18/5 Therefore, speed of the train = 20 18/5 km/hr = 72 km/hr