Question

A stone and a ball are thrown vertically upwards with different initial speeds 20m/s and 10m/s respectively. If the maximum height of the ball is h, what is the maximum height of the stone?

Answer 1

4h if there's no air resistance.

Step-by-step explanation:

Consider the equation that relates acceleration
`a`, displacement
`x`, initial velocity
`u`, and final velocity
`v`:

`\displaystyle x = (v^(2) - u^(2))/(2a)`.

For both the stone and the ball:

• 
  `a = g = \rm -9.81\; m\cdot s^(-2)`;
• 
  `v = \rm 0\;m \cdot s^(-1)` when the objects are at their highest point: all kinetic energy are converted to potential energy;

`x` is the height that needs to be found.

`\displaystyle x = (-u^(2))/(g)` for both objects.

`u` of the stone is twice that of the ball. As a result,
`u^(2)` of the stone will be four times that of the ball. As a result, the maximum height of the stone will be four times that of the ball.