Motion in A Str...

An object thrown vertically upwards with a velocity of 25 m/s takes 4 sec to reach the thrower. What is displacement of the object?

A ball is thrown upwards with a velocity of $$25 m/s$$. What is the time taken by the ball to return to the thrower ($$g=10\:m/s^2$$)

Assertion: The driver in a vehicle moving with a constant speed on a straight road is an inertial frame of reference.
Reason: A reference frame in which Newton's laws of motion are applicable is non-inertial.

A car accelerates steadily so that it goes from a velocity of 20 m/s to a velocity of 40 m/s in 4 seconds. What is its acceleration?  

Which of the following statement must always be true?

I.If an objects acceleration is zero, then its speed must remain constant.

II. If an objects acceleration is constant, then it must move in a straight line.

III. If an objects speed remains constant, then its acceleration must be zero.

The velocity-time graph below represents the velocity of a toy train as it moves north and south with velocity near the middle of the vertical axis. During which, Interval(s) is the toy train speeding up?

A sprinter starts from rest and accelerates at a steady rate for the first $$50 m $$ of a $$100 m$$ race, and then continues at a constant velocity for the second $$50 m$$ of the race. If the sprinter runs the $$100 m$$ in a time of $$10 s$$, what is his instantaneous velocity when he crosses the finish line? 

Which of the following vehicles is undergoing a deacceleration?

A girl is 13m away from a tree. An apple falls from the tree at height of 2.8 m. If she wants to catch the apple before it hits the ground then how fast does she need to run?

By applying brakes, a car moving at $$1 m{s}^{-1}$$ is brought to rest in 3 s. If it moves at $$2 m{s}^{-1}$$, how long will it take to come to rest?