One thing about rockets ... as they keep going, the force of the engines is constant, but they burn fuel, so their mass decreases, so their acceleration increases. It takes some awesome math (calculus) to keep track of their motion during the burn. But we'll do this problem the easy way ... just assume that the mass of the rocket doesn't change, even though the engines are giving it all they've got and burning tons of fuel.
Newton's second law of motion: Force = (mass) x (acceleration)
Force = (150 kg) x (75 m/s²)
Force = (150 x 75) (kg-m/s²)
Force = (150 x 75) Newtons
Force = 11,250 Newtons
