Question

A stone is thrown vertically upward with 20m/s. What is the time taken to reach its height?

Answer 1

To find the time taken for the stone to reach its maximum height, we can use the kinematic equation:

$v=u+at$

Where:

• v is the final velocity (which is 0 m/s at the highest point)
• u is the initial velocity (20 m/s)
• a is the acceleration due to gravity (-9.8 m/s²)
• t is the time taken

Substituting the known values into the equation:

$0=20-9.8t$

Solving for t:

$9.8t=20$ $t=\frac{20}{9.8}\approx 2.04\text{seconds}$

Therefore, it takes approximately 2.04 seconds for the stone to reach its maximum height.