A motor vehicle is brought to rest from a speed of 15ms-1 in 20 seconds. Calculate the retardation.
Answer Details
Retardation is the rate at which an object slows down. It is also known as deceleration or negative acceleration.
To calculate the retardation of the motor vehicle, we can use the following formula:
Retardation = (Final Velocity - Initial Velocity) / Time Taken
Here, the final velocity is 0 m/s (since the vehicle is brought to rest), the initial velocity is 15 m/s (given in the question), and the time taken is 20 seconds (also given in the question).
So, plugging in the values in the formula, we get:
Retardation = (0 - 15) / 20
Retardation = -0.75 m/s^2
Therefore, the retardation of the motor vehicle is 0.75 m/s^2 (option A).