Question

A body is moving vertically upwards. Its velocity changes at a constant rate from 50 m s⁻¹ to 20 m s⁻¹ in 3 s. What is its acceleration?

Answer 1

Here, final velocity = 20 m/s

Initial velocity = 50 m/s

Time taken = 3 s

Acceleration = `("Final Velocity" - "Initial Velocity")/"time"`

= `(20 - 50)/3` m/s⁻²

= −10 m/s⁻²

The negative sign here indicates that the velocity decreases with time, so retardation is 10 m/s⁻².