Question

If you are runnig at 6m/s and deceleration at 2m/s how long will it take you stop

a) 3 seconds
b) 4 seconds
c) 5 seconds
d) 6 seconds

Answer 1

a) 3 seconds

Step-by-step explanation:

• From first Newton's equation of motion;

`v = u - at`

where; v is final velocity

u is the initial velocity

a is the deceleration (it's negative because it is deceleration)

t is time

• From the question, you start running initially at 6m/s velocity, since it is deceleration, that means velocity will decrease till it reaches zero (v = 0)

`0 = u - (at) \\ u = at \: \: \: \: \: \: \: \: \: \: \: \: \: \\ 6 = (2t) \: \: \: \: \: \: \: \: \\ t = 3 \: s \: \: \: \: \: \: \: \: \: \:`

Answer 2

The time taken to stop when running at 6m/s with a deceleration of 2m/s is 0 seconds.

Step-by-step explanation:

The time it takes for the runner to stop can be calculated using the formula t = (v - u) / a, where t is the time, v is the final velocity, u is the initial velocity, and a is the deceleration.

For a) With a final velocity of 0 m/s and a deceleration of 2 m/s², the time taken to stop is t = (0 - 6) / 2 = -3 seconds. However, time cannot be negative, so the correct answer is 0 seconds.

For b) t = (0 - 6) / 2 = -3 seconds. Again, time cannot be negative, so the correct answer is 0 seconds.

For c) t = (0 - 6) / 2 = -3 seconds. Again, time cannot be negative, so the correct answer is 0 seconds.

For d) t = (0 - 6) / 2 = -3 seconds. Again, time cannot be negative, so the correct answer is 0 seconds.