Question

A sports car accelerates at 2.80 m/s2 along a straight road. At t1 = 5.00s and t2 = 5.50 s it passes two marks that are 35.0 m apart. What is the car's velocity at t0 = 0 s?​

Answer 1

Explanation:

Using kinematics,

s = ut + 0.5at².

We have s = 35.0m, t = 0.50s, a = 2.80m/s².

Substitute in the variables, we have u = 69.3m/s.

This u is only the initial velocity at t1. To find the velocity at t0, we apply a different kinematics equation with different values:

We have t = 5.00s, a = 2.80m/s², v = 69.3m/s.

Using kinematics,

v = u + at.

Substitute in the variables, we have u = 55.3m/s.

Hence the car's initial velocity is 55.3m/s.