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
What does the odometer of an automobile measure?
Name the physical quantity obtained by dividing ‘Distance travelled’ by ‘Time taken’ to travel that distance.
Arrange the following speed in increasing order (keeping the least speed first):
A bicycle moving with a speed of 200 m/min.
If a sprinter runs a distance of 100 metres in 9.83 seconds, calculate his average speed in km/h.
The diagram below shows the pattern of the oil on the road at a constant rate from a moving car. What information do you get from it about the motion of the car.
A car is moving in a straight line with speed 18 km h-1. It is stopped in 5 s by applying the brakes. Find:
- the speed of car in m s-1
- the retardation and
- the speed of car after 2 s of applying the brakes.
A body moves from rest with uniform acceleration and travels 270 m in 3 s. Find the velocity of the body at 10 s after the start.
What is the relation between distance and time when the body is moving with uniform velocity?
Give two examples of uniform circular motion from your daily life.
Distinguish between speed and velocity.
