Question

A biker goes from 15 ms -1to 0 ms -1after hitting a brick wall. Its rate of acceleration is -50ms -2 . Calculate the time taken for the bike to decelerate.

Answer 1

The time taken for the bike to decelerate from 15 m/s to 0 m/s with a deceleration rate of -50 m/s² is 0.3 seconds.

Step-by-step explanation:

To calculate the time taken for the bike to decelerate from 15 m/s to 0 m/s with a rate of acceleration of -50 m/s2, we will use the formula for deceleration (which is acceleration in the direction opposite to the velocity):

a = (Δv) / t

Where:

• 
  
• a is the acceleration (or deceleration)
• 
  
• Δv is the change in velocity
• 
  
• t is the time

Since the initial velocity u is 15 m/s, the final velocity v is 0 m/s, and the acceleration a is -50 m/s2, the formula to find time t is:

t = Δv / a

Substituting the values:

t = (0 - 15 m/s) / (-50 m/s2)

t = 15 / 50 seconds

t = 0.3 seconds

The time taken for the bike to decelerate is 0.3 seconds.

Answer 2

Time taken t = 4.167 seconds (Approx)

Step-by-step explanation:

Given:

Initial Speed u = 12 m/s

Final speed v = 0 m/s

Acceleration a = -50 m/s²

Find:

Time taken t

Computation:

v = u + at

0 = 12 + (-50)t

t = 4.167 s

Time taken t = 4.167 seconds (Approx)