Question

A bus travelling 80 km/h accelerates for 20 seconds to a speed of 100 km what is the acceleration 

Answer 1

We must first transform Km/h into m/s. This is easily done as follows:

Convert Km to m: 80Km = 80 000 m

Convert the “per hour” part (which just means that it is divided by): 1 hour = 3600 seconds.

Then we divide 80000 by 3600 to get 22.22 m/s

Then, by using the following Newtonian equation: V = v + at (where V is final velocity, v is initial velocity, a is acceleration and t is time. Later, by replacing the letters with numbers we get: 22.22 = 0+a*8 (solving to a) a=22.22/8 <=> a=2,775 m/s^2