Advertisements
Advertisements
प्रश्न
A car is moving with a velocity 20 m s-1. The brakes are applied to retard it at a rate of 2 m s-2. What will be the velocity after 5 s of applying the brakes?
Advertisements
उत्तर
Initial velocity of the car, u = 20 m/s
Retardation = 2 m/s2
Given time, t = 5 s
Let 'v' be the final velocity.
We know that, Acceleration = Rate of change of velocity/time
= (Final velocity - Initial velocity)/time
⇒ - 2 = `("v" - 20)/5`
⇒ - 2 × 5 = v - 20
⇒ - 10 = v - 20
⇒ - 10 + 20 = v
⇒ v = 10 m/s
Hence, final velocity = 10 m s-1.
APPEARS IN
संबंधित प्रश्न
During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, 3 × 108m s−1.
What do the following measure in a car ?
(a) Speedometer (b) Odometer
In addition to speed, what else should we know to predict the position of a moving body ?
State whether speed is a scalar or a vector quantity. Give reason for your choice.
Bus X travels a distance of 360 km in 5 hours whereas bus Y travels a distance of 476 km in 7 hours. Which
bus travels faster ?
A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:
How far does it travel in 6 seconds ?
A train takes 2 h to reach station B from station A, and then 3 h to return from station B to station A. The distance between the two stations is 200 km. Find:
The average speed,
The average velocity of the train.
A car moving on a straight path covers a distance of 1 km due east in 100 s. What is the speed of the car?
The velocity-time graph of a moving body is given below in Figure
Displacement in each part AB, BC and CD.
Define speed of a body.
