Question

A car initially traveling at 60 km/h accelerates at a constant rate of 2.0 m/s2. How much time is required for the car to reach a speed of 90 km/h

Answer 1

Answer:

Time, t = 4.165 seconds.

Explanation:

Given the following data;

Initial velocity = 60 km/h

Final velocity = 90 km/h

Acceleration = 2 m/s²

Conversion:

60 km/hr to meters per seconds = 60*1000/3600 = 60000/3600 = 16.67 m/s

90 km/hr to meters per seconds = 90*1000/3600 = 90000/3600 = 25 m/s

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

$V = U + at$

Where;

V is the final velocity.

U is the initial velocity.

a is the acceleration.

t is the time measured in seconds.

Making time, t the subject of formula, we have;

$t = \frac{V - U}{a}$

Substituting into the equation, we have;

$t = \frac{25 - 16.67}{2}$

$t = \frac{8.33}{2}$

Time, t = 4.165 seconds.