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 initial velocity ( v 0 ) and the braking capacity, or deceleration, ?a that is caused by the braking. A car travelling at speed 72km/hr suddenly applies the brake with the deceleration of 5m/s2. Find the stopping distance of the car -Science

1 Answer

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

Related questions

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 : 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 : If the velocity of moving vehicles on a road is 24 km/per hour, stopping distance is 19 metres and average length of vehicles is 6 metres, the basic capacity of lane, is (A) 500 vehicles per hour (B) 700 vehicles per hour (C) 1000 vehicles per hour (D) 1250 vehicles per hour

Last Answer : Answer: Option C

Description : In a braking test, a vehicle travelling at 36 km ph was stopped at a braking distance of 8.0 m. The average value of the vehicle's skid resistance (friction coefficient) is (A) 0.64 (B) 6.25 (C) 0.16 (D) None of these

Last Answer : Answer: Option C

Description : The ability of a driver to stop the vehicle moving with the designed speed, depends upon: (A) Perception time (B) Brake reaction time (C) Efficiency of the brakes (D) All the above

Last Answer : Answer: Option D

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 : If C is basic capacity per lane, V is velocity in km/hour, S is stopping distance plus length of the vehicles in metres, the formula C = 1000V/S is applicable to (A) District roads (B) Two lane roads (C) Two lane roads in one direction (D) None of these

Last Answer : Answer: Option C

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 : The distance travelled by a moving vehicle during perception and brake reaction times, is known as (A) Sight distance (B) Stopping distance (C) Lag distance (D) None of these

Last Answer : Answer: Option C

Description : One of the main advantages of disc brakes over drum brakes is that the disc brake : U. Can stop a vehicle in a shorter distance V. Is more heat resistant W. Weighs less than drum brakes X. Requires less pedal force to stop the vehicle

Last Answer : . Requires less pedal force to stop the vehicle

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 : If V is the velocity in kmph, t the stopping distance S of the vehicle, is (A) 0.28V²t + V/0.01 (B) 0.28Vt + V²/0.1 (C) 0.28Vt + 0.01 (D) 0.28Vt + 0.01 V²/

Last Answer : Answer: Option C

Description : A car is moving along a straight horizontal road at a speed of 20 meters per second. The brakes are applied and a constant force of 5000 Newtons decelerates the car to a stop in 10 seconds. The mass of the car is: w) 1250 kilograms x) 2500 kilograms y) 5000 kilograms z) 10,000 kilograms

Last Answer : ANSWER: X -- 2500 KILOGRAMS

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 : A truck of mass 5 ton is travelling on a horizontal road with 36 km hr^-1 stops on travelling 1 km after its engine fails suddenly.

Last Answer : A truck of mass 5 ton is travelling on a horizontal road with 36 km hr-1 stops on travelling ... similar distance same how much will the fraction be?

Description : If L is the length of vehicles in metres, C is the clear distance between two consecutive vehicles (stopping sight distance), V is the speed of vehicles in km/hour, the maximum number N of vehicles/hour, is (A) N = 1000 V / (L + C ... ) / 1000 V (C) N = 1000 L / (C + V) (D) N = 1000 C / (L + V)

Last Answer : Answer: Option A

Description : The purpose of 'R6' in the winch circuit shown in the illustration is to _______________. EL-0102 A. maintain dry conditions within the winch brake box B. keep the series field current at ... to assist the winch in stopping D. limit the armature current during lowering operation with heavy loads

Last Answer : Answer: C

Description : Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripheral velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πND where, N = speed of the rolls ... V.W.Dr.ρ (B) 3.6 V.W. ρ (C) 3.6 W.Dr.ρ (D) 3.6 V.W.Dr/ρ

Last Answer : (A) 3.6 V.W.Dr.ρ

Description : A boat takes 38 hrs for travelling downstream from point p to point q and coming back to a point r midway between p and q. If the velocity of the stream is 8 km/hr and the speed of the boat in still water is 28 km/hr. What is the distance between p and q? A) 720 B) 640 C) 510 D) 450

Last Answer : ANSWER: A Explanation: Speed downstream = (28 + 8)km/hr = 36 km/hr Speed upstream = (28 – 8)km/hr = 20 km/hr Let the distance between p and q be ‘x’km Then, x/36 + (x/2)/20 = 38 x/36 +x/40 = 38 19x = 13680 X = 720 km Therefore the distance between p and q is 720km

Description : The absolute minimum sight distance required for stopping a vehicle moving with a speed of 80 kmph, is (A) 120 m (B) 200 m (C) 640 m (D) None of these

Last Answer : Answer: Option A

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 person covered a certain distance by bus at the rate of 40 kmph and walked back to the initial point at the rate of 6 kmph. The whole journey took 13 hours and 48 minutes. What distance did he walk? a) 60km b) 64 km c) 70km d) 72km e) 80 km

Last Answer : Let the distance be x km. then (x/40) + (x/6) = 13 + (48/60) = 69/5 Answer is: d)

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

Description : Why do passengers lean forward when the moving vehicle suddenly brakes ?

Last Answer : When the bus is moving , the passengers get the same speed as the bus. When the bus suddenly brakes, the lower part of the body of the passenger is fixed with the bus , but the upper part of the body moves forward due to motion inertia so that the passengers lean forward.

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 car moving with a speed of 40 km/hr can be stopped by applying brakes after at least 2 m. If the same car is moving with a speed of 80 km/hr. What i

Last Answer : A car moving with a speed of 40 km/hr can be stopped by applying brakes after at least 2 m. If the same car is moving ... A. 2 m B. 4 m C. 6 m D. 8 m

Description : A bullet hits a Sand box with a velocity of 20 m/s and penetrates it up to a distance of 6 cm. Find the deceleration of the bullet in the sand box. -Science

Last Answer : 3333.3 m/s2 is the ans

Description : A speed boat moving at a velocity of 25 m/s runs out of gas and drifts to a stop 3 minutes later 100 meters away. What is its rate of deceleration?

Last Answer : 0.14 m/s²

Description : Regenerative braking (A) Can be used for stopping a motor. (B) Cannot be easily applied to DC series motors. (C) Can be easily applied to DC shunt motors (D) Cannot be used when motor load has overhauling characteristics.

Last Answer : Ans: B Because reversal of Ia would also mean reversal of field and hence of Eb

Description : The efficiency of the brakes of a vehicle depends upon (A) Condition of road surface (B) Condition of the tyres (C) Presence of the show moisture (D) All the above

Last Answer : Answer: Option D

Description : If A is the projected area of a vehicle in square metres, V is speed of the vehicles in kilometres per hour and C is a constant, then the wind resistance R to the moving vehicles, is given by (A) R = CAV (B) R = CAV2 (C) R = CAV3 (D) R = C 2AV

Last Answer : Answer: Option B

Description : Which of these is the purpose of power-split device a) To split Electrical Energy into Mechanical Energy. b) To allow both the engine and Electric motor to propel the vehicle c) To recharge the battery while braking d) To recharge the brakes while driving

Last Answer : b) To allow both the engine and Electric motor to propel the vehicle

Description : When brakes are applied on a moving vehicle the kinetic energy is converted to A. Mechanical energy B. Heat energy C. Electrical energy D. Potential energy

Last Answer : B. Heat energy

Description : ------------- is a feature that alerts a driver to an imminent crash and helps them use the maximum braking capacity of the car. a) AEB b) Air Bag c) Vehicles d) Electronic Stability control

Last Answer : a) AEB

Description : A this usual rowing rate, Mohit can travel 12 miles downstream in a certain river in 6 hours less than it takes him to travel the same distance upstream. But if he could double his usual rowing rate for his 24 miles round trip, ... current in miles per hour? A.2.5m/hr B.4 m/hr C.8/3 m/hr D. 5/3m/hr

Last Answer : Answer-C Basic Formula: Speed of the stream = ½ (a-b) km/hr Explanation: Let the speed in still water be x m/hr Speed of stream be y m/hr Then, speed upstream = x-y m/hr and Speed downstream = x+y m/hr 12/x-y - ... 1] 3y^2 = 8 y so, y = 8/3 speed of the current = 8/3 m/hr = 2 (2/3) m/hr

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 grinding wheel is rotating at 3000 rpm. When the switch is turned off the wheel stops in 10 seconds. The uniform deceleration of the wheel was a.1 rad/s2 b.31.4 rad/s2 c.4 rad/s2 d.62.8 rad/s2 e.10.4 rad/s2

Last Answer : b. 31.4 rad/s2

Description : An electron moving with a velocity of 5 10 3 m / s enters into a uniform electric field and acquires a uniform acceleration of 10 3 m / s 2 in the direction of initial velocity. i. ... which electron velocity will be doubled.? ii. How much distance electron would cover in this time.? -Science

Last Answer : Given u=5×103m/su=5×103m/s , a=103m/s2a=103m/s2, v=2u=104v=2u=104 m/s i.Using v=u+atv=u+at 104=5×103+103t104=5×103+103t or t=5 sec ii. Using s=ut+12at2s=ut+12at2 s=5×103×5+12×103×52s=5×103×5+12×103×52 =37.5×103m=37.5×103m

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 train, travelling at a uniform speed for 360 km, would have taken 48 minutes less to travel the same distance if its speed were 5 km/hr more. Find the original speed of the train. -Maths 10th

Last Answer : Let the speed of train be x km/hr Distance to be travelled = 360km We know that, Time take by the train intially = If the speed was increased by 5km/hr Time taken by train = Difference in the time taken is 48 minutes, x2+5x -2250 = 0 (x+50)(x-45) Speed = 45 km/hr as speed cannot be negative

Description : The traffic carrying capacity of a single lane, depends on (A) Type of the vehicles (B) Level crossings (C) Road intersections (D) All the above

Last Answer : Answer: Option D

Description : A particle of mass m is moving along a straight path through the origin of coordinates with a velocity v. The angular momentum of the particle about the origin (a) mv (b) Depends on its distance from origin (c) Is zero (d) Changes from positive to negative as it passes through the origin

Last Answer : Ans:(c)

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 : What happens to the stopping distance when the vehicle speed increases?

Last Answer : The distance needed to stop also increases.

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 : A van travels from namakkal to Madurai at a constant speed. If its speed were increased by 40km/hr it would have taken 1 hr lesser to cover the distance. It would have taken further 45 mins lesser if the speed ... by 40km/hr. what is distance between the 2 cities. a) 1680 b) B1660 c) 1670 d) 1675

Last Answer : A Let distance = x km Usual rate = y km/hr Then x/y - x/(y+40) =1 X(y+40) / y(y+40) = 1 Xy+40x - xy = y(y+40) 40x = y(y+40) ---------->1 x/y - x/y+80 = 7/4 x(y+80) - xy / y(y+ ... (y+80) / y(y+40) 8(y+40) = 7y + 560 8y +320 = 7y+560 Y=240 Substitute y value in 1 40x = 240*280 X=1680 km

Description : At an aircraft taxiing speed of 10mph, the anti-skid braking system is: a. Inoperative b. Operative c. Operative only on the nosewheel brakes d. Operative only on the main wheel brakes

Last Answer : a. Inoperative

Description : At an aircraft taxiing speed of 10mph, the anti-skid braking system is: a. Inoperative b. Operative c. Operative only on the nosewheel brakes d. Operative only on the main wheel brakes

Last Answer : a. Inoperative

Description : If brakes of vehicles are effective, the vehicle-running at 30 km/hour comes to a stop in (A) 10 metres (B) 12 metres (C) 15 metres (D) 18 metres

Last Answer : Answer: Option B