A body thrown upwards reaches the highest point in 2.0 s, find the velocity with which it was thrown. 

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A ball thrown upwards comes to a rest because of Earth's gravity, which tends to pull everything towards itself. Thus, the highest point of the ball is where it comes to a rest and its final velocity becomes 0. Using equation of motion:

v = u + at

where, v...

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A ball thrown upwards comes to a rest because of Earth's gravity, which tends to pull everything towards itself. Thus, the highest point of the ball is where it comes to a rest and its final velocity becomes 0. Using equation of motion:

v = u + at

where, v is the final velocity = 0 m/s

u is the initial velocity

a is the acceleration and is equal to -g or -9.81 m/s^2 (acceleration due to gravity of Earth)

and t is time taken = 2 s

Substituting all the parametric values in the equation, we get:

0 = u + (-9.81 x 2)

or, u = 19.62 m/s.

Thus, the ball was thrown upwards with an initial speed of 19.62 m/s.

In general, anything that is thrown upwards is pulled down due to gravity and hence loses speed. Anything thrown downwards, gains speed due to acceleration due to gravity.

Hope this helps. 

 

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