A hot air balloon rises vertically.At time $t=0$, a ball is released from the balloon. This graph shows the variation of the ball's velocity $\mathrm{v} \mathrm{with} \mathrm{t}$. The ball hits the ground at $\mathrm{t}=4.1 \mathrm{s}$

Use the graph to determine the distance between the highest point reached by the ball and the ground.

 

A hot air balloon rises vertically.At time $t=0$, a ball is released from the balloon. This graph shows the variation of the ball's velocity $\mathrm{v} \mathrm{with} \mathrm{t}$. The ball hits the ground at $\mathrm{t}=4.1 \mathrm{s}$

The equation relating $v and t$ is $v=15-9.81 \mathrm{t}$. State the significance in the equation of the number $15$.

A hot air balloon rises vertically.At time $t=0$, a ball is released from the balloon. This graph shows the variation of the ball's velocity $\mathrm{v} \mathrm{with} \mathrm{t}$. The ball hits the ground at $\mathrm{t}=4.1 \mathrm{s}$

The equation relating $v and t$ is $v=15-9.81 \mathrm{t}$. State the significance in the equation of the negative sign.

An aeroplane is travelling horizontally at a speed of $80 m{s}^{-1}$ and drops a crate of emergency supplies To avoid damage, the maximum vertical speed of the crate on landing is  $20 {\mathrm{ms}}^{-1}$. You may assume the air resistance is negligible.

Calculate the maximum height of the aeroplane when the crate is dropped. 

An aeroplane is travelling horizontally at a speed of $80 m{s}^{-1}$ and drops a crate of emergency supplies To avoid damage, the maximum vertical speed of the crate on landing is  $20 {\mathrm{ms}}^{-1}$. You may assume the air resistance is negligible.

Calculate the time taken for the crate to reach the ground from this height.

An aeroplane is travelling horizontally at a speed of $80 m{s}^{-1}$ and drops a crate of emergency supplies To avoid damage, the maximum vertical speed of the crate on landing is  $20 {\mathrm{ms}}^{-1}$. You may assume the air resistance is negligible.

The aeroplane is travelling at the maximum permitted height.Calculate the horizontal distance travelled by the crate after it is released

from the aeroplane.