Answer:
Speed at which it will reach the ground is given as

Total time for which it will remain in air is given as
t = 6.3 s
Explanation:
As we know that the object is projected upwards with speed


now when it will reach the ground then we have

so we have


so we have

Now speed of the object when it reaches the ground is given as



Answer:
a) 
b) 
Explanation:
Given:
- initial rotational speed of phonograph,

- final rotational speed of phonograph,

- time taken for the acceleration,

a)
Now angular acceleration:



b)
Using eq. of motion:



Multiply these numbers and there’s your answer
Answer:
c
Explanation:
The car travels with centripetal acceleration which is directed to the center of the circle but the velocity is changing since the car faces different direction as it travels in the circular direction. When the friction is zero between the tires of the car and the road, it will continue in the direction of its tangential velocity which will be along a straight-line path in its original direction.