Compare the time taken by the RC car to cover the same distance. Do some go faster or slower?

There isn; t enough given values to define and determine what is asked. But since

distance = speed / time, time = distance / speed

Calculate the acceleration of a boat that has been cruising at 15 m/s but speeds up to 45 m/s in about 6 seconds. Don’t forget your units, m/s2. In order to calculate the acceleration of the boat we first have to identify the suited formula for acceleration in this scenario.

Hence, a = vf - vi / t. Vi = 15 m/s Vf = 45 m/s T = 6 seconds

Solution:

A = 45 m/s - 15m/s / 6s

A = 5m/s^2