Question

A bike is travelling at a velocity of 7 m/s. The cyclist brakes for 2 seconds when a dog runs out in front of her. The bike's new velocity is 4 m/s. Calculate the acceleration of the bike.

Answer 1

Answer:

Explanation:

For an acceleration of a

v(t) = at + c

initial velocity = 7 m/s

7 = a(0) + c

so v(t) = at + 7

when t = 2, v(2) = 4

4 = 2a + 7

2a = -3

a = -3/2

The bike decelerated at 3/2 m/s^2 or it accelerated at -3/2 m/s^2

Answer 2

a = (v-u)/t

a = 4-7 /2

a = -1.5m/s^2.

Hope it helps