Question

If a car travels 23.8 meters in 4.2 seconds, what is its speed?

Put your units in the form of a correct abbreviation (example, write s for seconds, m
for meters, or m/s for meters per second).

Answer 1

Displacement = Initial Velocity * time + 0.5 * acceleration * time^2

Initial velocity * time = 0 since we assume that the car is launching from start without motion.

So, displacement = 0.5 * acceleration * time ^ 2

23.8 = 0.5 * acceleration * 4.2^2

23.8 = 0.5 * 17.64 * acceleration

23.8 = 8.82 * acceleration

23.8/8.82 = acceleration = 2.69 m/s^2

Final Velocity = initial velocity + acceleration * time

Final velocity = 0 + 2.69 * 4.2 = 11.3 m/s