Question

An eraser is thrown upward with an initial velocity of 5.0 m/s. The eraser's velocity after 7.0 seconds is ____ m/s.

Answer 1

Given parameters:

Initial velocity of eraser  = 5.0m/s

Time  = 7.0s

Unknown:

Final velocity = ?

Solution:

Since we have been given the initial velocity and duration of the throw, we can apply the appropriate motion equation to solve this problem.

       V  = U - 2gt

where V is the final velocity

            U is the initial velocity

             g is the acceleration due to gravity = 9.8m/s²

            t is the time taken

       V  = U - gt

       V = 5 - (9.8)(7)

       V = -63.6 or -64m/s

The velocity is -64m/s