A constant force of 100N , directed upward, is applied to a 5.0kg toy rocket by the rocket's engine.

What is the rocket's acceleration?

I used the equation a= F/m to get 20 m/s2 but it was wrong and I don't know where to go from here still?

1 answer

You forgot the weight

weight = m g = 5(9.81) = 49 N

so 100 N up, 49 down
net force = 51 N up

a = F/m 51/5 = 10.2 m/s^2