Question

A student drops a ball from the top of a tall building; it takes 2.9 s for the ball to reach the ground.

Answer 1

We have,

• Initial velocity (u) = 0 m/s
• Time taken (t) = 2.9s
• Acceleration due to gravity (g) = + 10 m/s² [Down]

To calculate,

• Final velocity (v)
• Height (h)

Solution,

→ v = u + gt

→ v = 0 + 10(2.9)

→ v = 29 m/s $\qquad$ … ( Ans )

And,

→ h = ut + ½gt²

→ h = 0(2.9) + ½ × 10 × (2.9)²

→ h = 5 × 8.41

→ h = 42.05 m $\qquad$ … ( Ans )