Description : An object dropped from a cliff falls with a constant acceleration of 10 m/s2. Find its speed 5 s after it was dropped. -Science
Last Answer : v=u+atv=u+at u=0u=0 v=10×5=50m/sv=10×5=50m/s
Description : An object moves along a straight line with an acceleration of 2 m/s2. If its initial speed is 10 m/s, what will be its speed 2 s later? -Science
Last Answer : u=10 m/s,t=2 s, a=2 m/s2 v=u+atv=u+at v=10+2×2=14v=10+2×2=14 m/s
Description : A ball moving with uniform velocity comes to rest in a distance of 72 m in 6 s. Its initial velocity and retardation are (a) 12 m/s and 2 m/s2 (b) 12 m/s and 4 m/s2 (c) 24 m/s and 8 m/s2 (d) 24 m/s and 4 m/s2
Last Answer : Ans:(d)
Description : A car starts from rest and moves on a straight road with a uniform acceleration of 10 m/s2 for the first 10 s. During the next 10 s, the car move s with the velocity it has attained. What is the total distance covered by the car in 20 s? (a) 500 m (b) 1000 m (c) 1,500 m (d) 2,000 m
Last Answer : Ans:(c)
Description : A satellite orbits the earth 200 km above the surface. What speed, in m/s, is necessary for a circular orbit? The radius of the earth is 6400 km and g = 9.2 m/s2 a.7200 b.6600 c.7800 d.6000 e.107 dynes
Last Answer : c. 7800
Description : A motor boat whose speed is 18 km/h in still water takes 1 hour more to go 24 km upstream than to return downstream to the same spot. Find the speed of the stream. -Maths 10th
Last Answer : The given speed of the motor boat in the still water is equal to 18 km/ hr. The given distance travelled by motor boat is equal to 24 km. The time taken to travel 24 km downstream by motor boat = 1 hour. x=122=6 km/ hr.
Description : The common acceleration will be a.1.5 m/s2 b.1.0 m/s2 c.107 dynes d.6 m/s2 e.3 m/s2
Last Answer : b. 1.0 m/s2
Description : Maximum acceleration in above problem is a.107 dynes b.2?2/3 m/s2 c.?2/s m/s2 d.3?2 m/s2 e.4?2/9 m/s2
Last Answer : e. 4?2/9 m/s2
Description : A roller coaster reaches a velocity of 20 m/s at a location where the radius of curvature is 40 m. Calculate the acceleration in m/s2? a.10 b.9 c.11 d.8 e.107 dynes
Last Answer : a. 10
Description : A imaginary planet has half the mass and half the radius of the earth. The acceleration of gravity at its surface would be a.9.8 m/s2 b.107 dynes c.4.9 m/s2 d.19.6 m/s2 e.2.45 m/s2
Last Answer : d. 19.6 m/s2
Description : Speed of snail as compared to speed of a car will be in units A. cm s-1 B. m s-1 C. km s-1 D. km h-1
Last Answer : cm s-1
Description : Over taking time required for a vehicle with design speed 50 km ph and overtaking acceleration 1.25 m/sec2 to overtake a vehicle moving at a speed 30 km ph, is (A) 5.0 secs (B) 6.12 secs (C) 225.48 secs (D) 30 secs
Last Answer : Answer: Option B
Description : The breaking strength of a rope is 400 N. A fireman weighing 60 kg slides down the rope. The rope will break if a.107 dynes b.the acceleration is 7.5 m/s2 c.the acceleration is 1.2 m/s2 d.the acceleration is 3.1 m/s2 e.the slides with an acceleration of 15 m/s2
Last Answer : c. the acceleration is 1.2 m/s2
Description : A weight of 4.9 N rests on a rough horizontal floor that has a coefficient of friction of 0.5. If g = 9.8 m/s2, the smallest horizontal force that gives the weight an acceleration of 4m/s2 is most nearly a.2.5 N b.3 N c.2 N d.4.5 N e.4.9 N
Last Answer : d. 4.5 N
Description : If a car starting from rest reaches a velocity of 18 m s-1 after 6.0 s then its acceleration is A. 1 m s-2 B. 2 m s-2 C. 3 m s-2 D. 4 m s-2
Last Answer : 3 m s-2
Description : The distance between two stations ooty and chennai is 615km. A train with speed of 75 km/h leaves ooty at 8:00 am towards chennai. Another train with speed of 105 km/h leaves Chennai at 9 : 00 am towards ooty . Then, at what time both trains meet? A) 6 B) 12 C) 18 D) 24
Last Answer : ANSWER:B Explanation: First train leaves at 8.00am and second leaves at 9.00am So,first train that is , from ooty to Chennai has covered 75 km distance in 1 hr. So , distance left by between the station = ... the trains will meet , 3 hr after second train left i.e., 9.00 am +3 = 12.00 pm
Description : In the above problem, acceleration of crooshead at 30? phase equals a.107 dynes b.640 m/s2 c.780 m/s2 d.520 m/s2 e.870 m/s2
Last Answer : e. 870 m/s2
Description : Our weight will be zero under all of the following conditions EXCEPT a.107 dynes b.We are at the centre of the earth c.When we are ascending in a lift with acceleration of 4.9 m/s2 d.We are orbiting in a satellite e.When we are freely faling
Last Answer : c. When we are ascending in a lift with acceleration of 4.9 m/s2
Description : two soccer players kick the same 2-kg ball at the same time in opposite directions One kicks with a force of 15N the other kicks with a force of 5N. what is the resulting acceleration of the ball, in m/s2?
Last Answer : 5
Description : A train accelerates from 36 km/h to 54 km/h in 10 sec. (i) Acceleration (ii) The distance travelled by car. -Science
Last Answer : a. Acceleration is given by a=ΔvΔta=ΔvΔt Δv=54−36=18km/hr=18×10003600m/s=5m/sΔv=54−36=18km/hr=18×10003600m/s=5m/s So a=.5 m/s2 b. Distance is given by S=ut+12at2S=ut+12at2 Now u=36 km/hr =10m/s s=10×10+12×.5×102s=10×10+12×.5×102 So s=125m
Description : The displacement of a particle under going rectilinear motion along the x-axis is given by x = 2t3 + 21t2 + 60t + 6 metres. a.27 m/s2 b.18 m/s2 c.36 m/s2 d.9 m/s2 e.107 dynes
Last Answer : d. 9 m/s2
Description : Find the speed and average speed of a bus which leaves salem at 4 p.m. and reaches madurai in the same day at 8 p.m. The distance between the two stations is 216 km and the total time for stoppage is 1 hour between these stations. a) 54,72 b) 62,84 c) 72,54 d) 82,64
Last Answer : C Total time taken = 4 hours; Time of stoppage = 1 hour, that is, actual time taken = 4 hours - 1 hours = 3 hours Speed = Distance/Time = 216/3 = 72 km/hr Average speed = Total Distance/ Total Time = 216/4 = 54 km/hr
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 : Permitted wind velocity for running of trains on the bridge a) 72 km/h* b) 58 km/h c) 64 km/h d) No limits
Last Answer : a) 72 km/h*
Description : If a transmitting antenna is 100 meters high and a separate receiving antenna is 64 meters high, what is the maximum space wave communication distance possible between them? A. 18 km B. 72 km C. 164 km D. 656 km
Last Answer : B. 72 km
Description : An engineer is asked to design a playground slide such that the speed a child reaches at the bottom does not exceed 4.0 m/s. Determine the maximum height that the slide can be.?Given, g = 9.8 m/s2. -Physics 9th
Last Answer : Entire PE is converted to KE when the child reaches bottom So KE = PE 12mv2=mgH12mv2=mgH or H=v22g=162×9.8=.816mH=v22g=162×9.8=.816m
Description : While traveling in a straight line, a car uniformly changes its speed from 50 kilometers per hour to 110 kilometers per hour in 5 seconds. The acceleration of the car during this time is: w) 5 ... per hour per second y) 50 kilometers per hour per second z) 60 kilometers per hour per second
Last Answer : ANSWER: X -- 12 KILOMETERS PER HOUR PER SECOND
Description : A 2 m long shaft rotates about one end at 20 rad/s. It begins to accelerate with ? = 10 rads/s2. After how long, in seconds, will the velocity of the free end reach 100 m/s? a.3 b.107 dynes c.5 d.6 e.7
Last Answer : a. 3
Description : A bus can travel 25% faster than a jeep. Both start from point P at the same time and reach point Q, 225 kms away from P, at the same time. On the way, however, the bus lost about 37.5 minutes while stopping at the ... is the speed of the jeep? a) 64 km/hr b) 72 km/hr c) 68 km/hr d) 56 km/hr
Last Answer : B Let speed of the jeep =x kmph Then, speed of the bus =(100+25)x/100 =125x/100 =5x/4 kmph Time taken by the jeep to travel from P to Q =225/x hours Time taken by the bus to travel from p to Q =225/(5x/4) + ... 225/x=900/5x+37.5/60 225/x=180/x+37.5/60 45/x =37.5/60 37.5x=45*60 X=72 km/hr
Description : An automobile is travelling at 25 m/s. It takes 0.3 second to apply the brakes after which the deceleration is 6 m/s2. How far, in meters, does the automobile travel before it stops? a.45 b.107 dynes c.40 d.50 e.60
Last Answer : e. 60
Description : Anand leaves his house at 8.30 A.M for his school. The school is 2 km away and classes start at 9.00 A.M. If he walks at a speed of 3 km/h for the first kilometre, at what speed should he walk the second kilometre to reach just in time? -Science
Last Answer : speed=distancetimespeed=distancetime or time=distancespeedtime=distancespeed For travelling 1 km with 3 km/hr, Time taken = 1/3 hr = 20 min Now he has to reach school in 30 min,So he has cover another 1 km in = 30 -20 =10 min= 1/6 hr So speed should = distance /time= 1/(1/6) = 6 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 : 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 : 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 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 : There is a bridge besides a river. Two friends Arun and varun started their journey from place L, moved to the garden located at another place M & then returned to place L. Arun moves by swimming at a speed of 30 ... 12km/hr, what will be the average speed of boat sailor? A) 36 B) 18 C) 24 D) 48
Last Answer : ANSWER:B Explanation: As Arun swims both the ways at the speed of 30km/hr, the average speed of swimming is 30 km/hr Being a boat sailor, varun moves downstream at speed =24 +12=36km/hr and upstream at speed = 24-12= ... Upstream Speed])] = (36*12)/0.5(36+12) km/hr = 432/24 km/hr = 18 km/hr
Description : Two cars A and B race each other. The Car A ran for 2 minute at a speed of 7.5 km/h, slept for 56 minute and again ran for 2 minute at a speed of 7.5 km/h. find the average speed of the car A in the race. -Science
Last Answer : We know that Distance=speed×timeDistance=speed×time Distance travelled in first 2 minute = 7.5×2607.5×260 = 0.25 km Distance travelled in last 2 minute = 7.5×2607.5×260= 0.25 km Total distance = .25+.25 = 0.5 km Total time = 2+2+56 = 60 minute = 1 hr Average speed = 0.5/1 = 0.5 km/hr
Description : Calculate the acceleration due to gravity at a height of 300 km from the surface of the Earth. (M = 5.98 × 10^24 kg, R = 6400 km).
Last Answer : Calculate the acceleration due to gravity at a height of 300 km from the surface of the Earth. (M = 5.98 × 1024 kg, R = 6400 km).
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 : How long in a car would it take to drive km in the average speed of 65km/h?
Last Answer : Please enter the speed and distance values to calculate the travel time in ... How long would it take for someone to travel 2000mile in a car average speed 40mph ... How long will it take to cover the distance at an average speed of 75 km/h
Description : Excluding the stoppages, the speed of a bus is 64 km/hr and including the stoppages the speed of the bus is 48km/hr. For how many minutes does the bus stop per hour? 1) 15 min 2) 10 min 3) 12 min 4) 20 min 5) 18 min
Last Answer : 1) 15 min
Description : If is the speed of a locomotive in km per hour, g is the acceleration due to gravity, is the distance between running faces of the rails and is the radius of the circular curve, the required super elevation is (A) gV²/GR (B) Rg/GV² (C) GR/gV² (D) GV²/gR
Last Answer : (D) GV²/gR
Description : If V is the design speed of vehicles in km/hour, the change of radial acceleration in metres/sec3 , is (A) 65/(70 + V) (B) 60/(70 + V) (C) 70/(65 + V) (D) 70/(60 + V)
Last Answer : Answer: Option C
Description : A boat is rowed downstream at 15.5 km/h and upstream at 8.5 km/h. The speed of the stream is: (a) 3.5 km/h (b) 5.75 km/h (c) 6.5 km/h (d) 7 km/h
Last Answer : (a) 3.5 km/h
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 : If a Rajdhani train running at the speed of 25 m/s and covers 0.8 km long chunk in 6 minutes, then the length of the train is: A) 8.2 B) 6.7 C) 7.5 D) 9.3
Last Answer : ANSWER:A Explanation: Speed of the train = 25 m/s. Length of the chunk = 0.8 km = 800 meters Time taken to cross the chunk = 6 minutes = (6*60) seconds = 360 seconds Let the length of the train be y ... +y = 9000 y = 8200 m i.e., y = 8.2 km Hence the length of the train is 8.2 km
Description : A rocket is fired vertically from the ground with a resultant vertical acceleration of 10 m/sec the fuel is finished in one minute and it continues to move up. The maximum height reached will be a.2 km b.20 km c.36 km d.10 km e.80 km
Last Answer : a. 2 km
Description : A motor car starts with the speed of 70 km/hr with its speed increasing every two hours by 10 kmph. In how many hours will it cover 345 kms? A.4 hrs B.4 hrs 5 mins C.4 1/2 hrs D.2 hrs E.None of these
Last Answer : Answer - C (4 1/2 hrs) Explanation - Distance covered in first 2 hours = (70 x 2) km = 140 km Distance covered in next 2 hours = (80 x 2) km = 160 km Remaining distance = 345 - (140 + 160) = 45 km. Speed in the ... ..1 hr 45km .? ?=45/90hr=1/2hr Total time taken = 2 + 2 +1/2=4 (1/2)hrs
Description : Find the electric field applied on a system with electrons having a velocity 5m/s subjected to a magnetic flux of 3.6 units. a) 15 b) 18 c) 1.38 d) 0.72
Last Answer : b) 18
Description : The combined mass of car and passengers travelling at 72 km/hr is 1500 kg. Find the kinetic energy of this combined mass. (Formula: K =mv2 / 2k ) a. 300 kJ b. 200 kJ c. 500 kJ d. None of the above
Last Answer : 300 kJ