Question

A bicycle rider increases his speed from 5 m/s to 15 m/s in while accelerating at 2.5 m/s2. How long does this take ?

Answer 1

Answer:

4 seconds

Explanation:

Average acceleration is change in velocity over change in time:

a = Δv / Δt

Δt = Δv / a

Δt = (15 m/s - 5 m/s) / 2.5 m/s²

Δt = 4 s

Answer 2

Answer: The time taken by the bicycle rider is 4 seconds.

Explanation:

To calculate the time taken by the rider, we use first equation of motion:

$v=u+at$

where,

v = final velocity of the rider = 15 m/s

u = initial velocity of the rider = 5 m/s

a = acceleration of the car = $2.5m/s^2$

t = time taken = ?

Putting values in above equation, we get:

$15=5+(2.5\times t)\\\\t=\frac{15-5}{2.5}\\\\t=4s$

Hence, the time taken by the bicycle rider is 4 seconds.