Question

1. A car is travelling at 20 km/h, it speeds upto 60 km/h in 6 seconds. What is its acceleration?

2. A car accelerates from 6 ms–1 to  16 ms–1 in 10 sec.
Calculate 
 (a)  the acceleration and
 (b)  the distance covered by the car in that time.


3. A toy car accelerates from 3m/s to 5m/s in 5 s. What is its acceleration?

4. Which speed is greater: 30 m/s or 30 km/h?

5. The driver of train A travelling at a speed of 54 kmh-1 applies brakes and retards the train uniformly. The train stops in 5 seconds.
Calculate the acceleration.

6. A body starts to slide over a horizontal surface with an initial velocity of 0.5 m/s. Due to friction, its velocity decreases at the rate 0.05 m/s2. How much time will it take for the body to stop?

7. A ball hits the wall horizontally at 6m/s. It rebounds horizontally at 4.4m/s. The ball was in contact with wall for 0.040 seconds.
What is the acceleration of the ball ?​

Answer 1

Answer:

3. a=v-u/t

5-3/5

2/5

0.4m/s2

4. 30 km/h can be written as

30×5÷18 m/s

8.332 m/s

So unquestionably, 30 m/s is greater than 30 km/h i.e 8.33 m/s

6. u=0.5 m/s

a=-0.05 m/s^2

v=0

By first equation of motion , we have :

v=u+at

0=0.5-0.05t

0-0.5=-0.05t

-0.5=-0.05t

0.5/0. 0.05=t

50/5=t

10s=t