Advertisements
Advertisements
Question
A racing car is moving with a velocity of 50 m/s. On
applying brakes, it is uniformly retarded and comes to rest in 20 seconds. Calculate its acceleration.
Advertisements
Solution
Initial velocity of car = u = 50 m/s
Final velocity of car = v = 0 .......[∵ As car comes to rest]
Time = t = 20s
Acceleration = a = ?
v = u + at
0 = 50 + a(20)
−20a = 50
a = `(-50)/20` = −2.5 ms−2
APPEARS IN
RELATED QUESTIONS
A vehicle is accelerating on a straight road. Its velocity at any instant is 30 km/h. After 2 s, it is 33.6 km/h, and after further 2 s, it is 37.2 km/h. Find the acceleration of the vehicle in m s-2. Is the acceleration uniform?
A ball is rolling from A to D on a flat and smooth surface. Its speed is 2 cm/s. On reaching B, it was pushed continuously up to C. On reaching D from C, its speed had become 4 cm/s. It took 2 seconds for it to go from B to C. What is the acceleration of the ball as it goes from B to C?
Diagram is given below shows velocity – time graph of car P and Q, starting from the same place and in the same direction. Calculate the Acceleration of car Q between 2 s – 5 s.
A racing car, initially at rest, picks up a velocity of 180 kmh−1 in 4.5 s. Calculate
- acceleration
- distance covered by the car.
Write the SI unit of retardation.
Write the SI unit of acceleration and retardation.
What happens to the stepwise increasing speed-time graph when the size of each step is made very small?
A car accelerates to a velocity of 30 m/s in 10 s and then decelerates for 20 s so that it stops. Draw a velocity-time graph to represent the motion and find:
The Deceleration.
A bus can accelerate with an acceleration of 1 m/s2 . Find the minimum time for the bus to attain the speed of 100 km/s from 50 km /s.
Negative acceleration is called ______.
