Question

Lucy moves down the hall at 3.5 m/s. When he sees Luke coming, he slows down. After 4.0 s, he is moving at 2.1. m/s. What is his acceleration?​

Answer 1

Answer:

Acceleration, a = 0.35 m/s²

Explanation:

Given the following data;

Initial velocity, u = 3.5 m/s²

Final velocity, v = 2.1 m/s²

Time, t = 4 secs

To find the acceleration, we would use the first equation of motion;

V = u - at (the sign is negative because Lucy is slowing down).

Substituting into the formula, we have;

2.1 = 3.5 - a(4)

2.1 = 3.5 - 4a

4a = 3.5 - 2.1

4a = 1.4

a = 1.4/4

a = 0.35 m/s²