Question

A ball is thrown vertically upwards with an initial velocity of 22 m/s. When will its speed be 10

m/s?

Answer 1

The ball's speed will be 10 m/s at t=1.22 seconds

Explanation:

The vertical motion of an object is controlled by the force of gravity. This means that there is a non-zero net force acting on the object that makes it accelerate downwards.

If the object is thrown upwards at speed vo, its speed at time t is:

`v_f=v_o-g.t`

Where g is the acceleration of gravity
`g=9.8 m/s^2.`

Our ball is thrown upwards with v0=22 m/s. We need to calculate the time when its speed is vf=10 m/s.

Solving the above equation for t:

`\displaystyle t=(v_o-v_f)/(g)`

Substituting:

`\displaystyle t=(22-10)/(9.8)=(12)/(9.8)`

t=1.22 seconds

The ball's speed will be 10 m/s at t=1.22 seconds