A sled is accelerating at 2 m/s2 because it is being pushed on ice by Jenny. Tommy then jumps on the sled (he has the same mass as the sled). What has happened to the total mass Jenny is pushing, compared to before?

The acceleration of the total mass decreases by half (1/2)

Explanation:

Given;

acceleration of sled = 2 m/s²

From Newton's second law of motion, F = ma

⇒m = F/a

F is the force applied by Jenny

This force applied by Jenny should be the same, after Tommy jumps on the sled, but the acceleration will change.

F = m₁a₁ = m₂a₂

Since m₂ = 2m₁, then we calculate a₂

m₁a₁ = 2m₁a₂

a₂ = a₁/2

Therefore, The acceleration of the total mass decreases by half.