A car starts from rest and drives in a straight line for the next 3.8 km distance in the East direction

Question

A car starts from rest and drives in a straight line for the next 3.8 km distance in the East direction with a constant horizontal acceleration. If it took 10 minutes for the car to travel that 3.8 km;

   What is the acceleration of the car?

Answer 1

Using the kinematic formula x = v_ot + (1/2)at² , first we recognize that the car starts from rest which means that v_o = 0. The equation then simplifies to x = (1/2)at².

Since you need to solve for the acceleration, a, solve the equation for a. Multiplying both sides by 2 and then dividing by t², we see that a = (2x) / t².

If you want the acceleration in km/min², just substitute the 3.8 for x and the 10 for t. If you want the acceleration in km/s², then convert the 10 minutes into seconds. If you want m/s², then convert the 3.8 km to meters and the 10 minutes to seconds before substituting. :)

Hope this helps.