Answer:
"If the force applied to a cart is increased, then the acceleration of the cart increases, because acceleration is directly proportional to the force applied. If the mass of the cart is increased, then the acceleration decreases, because acceleration is inversely proportional to the mass."
Explanation:
This sentence can be explained by Newton's second law:

where
F is the net force acting on the cart
m is the mass of the cart
a is the acceleration of the cart
We can re-write it solving for a:

this way, we see that:
- acceleration is directly proportional to the force: if the force increases, the acceleration increases
- acceleration is inversely proportional to the mass: if the mass increases, the acceleration decreases