Question

A bus is moving at 20 m/s and slows at a rate of 4 m/s² each second. What is the velocity of the bus after 5 seconds?

a) 0 m/s
b) 5 m/s
c) 10 m/s
d) 15 m/s

Answer 1

To find the velocity of the bus after 5 seconds, multiply the deceleration (4 m/s²) by the time (5 seconds) to get 20 m/s. Subtract this from the initial velocity of 20 m/s to get 0 m/s. Thus, the correct answer is (a) 0 m/s.

Step-by-step explanation:

The student's question asks about the change in velocity of a bus slowing down at a constant rate over a period of time. This is a classic physics problem involving deceleration (negative acceleration). The initial velocity of the bus is 20 m/s, and the bus slows at a rate of 4 m/s² each second. To find the velocity of the bus after 5 seconds, you simply multiply the rate of deceleration by the number of seconds and subtract this from the initial velocity.

The calculation is as follows:

• Deceleration over 5 seconds = 4 m/s² * 5 s = 20 m/s
• Final velocity = initial velocity - deceleration = 20 m/s - 20 m/s = 0 m/s

Therefore, the velocity of the bus after 5 seconds is 0 m/s, which corresponds to option (a).