## Question

A body is thrown vertically up from the ground with an initial speed u and it reaches the maximum height h at time t_{0}.

What is the height it reaches at ½ t_{0}?

## Answer

We first define the upwards direction as positive.

When the body reaches the maximum height, the speed of the body is 0.

Knowing this, we can find expressions for h and t_{0}. The acceleration of the body is taken to be 10 ms^{-2} downwards. Since we define upwards to be positive, the acceleleration will be -10 ms^{-2}.

When the time is ½ t_{0},

Now that we know the speed at ½ t_{0}, we can find the height travelled by the body.