Question

A student builds a rocket-propelled cart for a science project. Its acceleration is not quite high enough to win a prize, so he uses a larger rocket engine that provides 36% more thrust, although doing so increases the mass of the cart by 11%. By what percentage does the cart's acceleration increase?

Answer 1

From Newton #2 . . . F = M A

We'll be looking for acceleration, so before we start, let's divide each side of Newton #2 by (mass) :  A = F / M .  

Original acceleration = F / M

New acceleration = (1.36 F) / (1.11 M)

New acceleration = (1.36 / 1.11) (F / M)

New acceleration = (1.23) (F/M)

New acceleration = (1.23) (original acceleration)

Using the bigger rocket engine increases the acceleration by 23% .