17. A force of 30.0 N is applied in the positive x-direction to a block of mass 8.00 kg, at rest on a frictionless surface. (a) What is the block's acceleration? (b) How fast is it going after 6.00 s?

Commercial airplanes are sometimes pushed out of the passenger loading area by a tractor. (a) The 1800 kg tractor exerts a force of 1.80 × 104 N backward on the pavement, and the system experiences forces resisting motion that total 2400 N. If the acceleration is 0.170 m/s2, what is the mass of the airplane in kilograms? kg (b) Calculate the force (in N) exerted by the tractor on the airplane, assuming 2250 N of the friction is experienced by the airplane. N

A freight train has a mass of 1.5 × 107 kg. If the locomotive can exert a constant pull of 7.5 × 105 N, how long does it take to increase the speed of the train from rest to 80 km/h?

a car of mass 2.0*10^3 kg is initialy moving at 21 m/s when the brakes are applied and the car is brought to stop in 25m. Assuming the force that the stops the car is constant, find the magnitude of that force that stop the car?