An airplane starts from rest on the runway. The engines exert a constant force of 78.0 kN on the body of the plane (mass 9.20 × 104 kg) during takeoff. How far down the runway does the plane reach its takeoff speed of 64.6 m/s?

You are pushing a wooden crate against a rubber floor. The two surfaces have a static coefficient of friction of 0.45 and a kinetic coefficient of friction of 0.38. The floor is horizontal, and the crate has a mass of 25.0 kg, and is initially at rest. You are pushing with a horizontal force of 155 N. What is the magnitude of the force of friction in this case? Give your answer in units of N, to three significant figures.

OK, same sort of track, but now with d = 4.63 m. Now suppose the blocks starts on the track at x = 4.73 m. The block is given a push to the left and begins to slide up the track, eventually reaching its maximum height at x = 0, at which point it turns around and begins sliding down. What was its initial speed in this case?     13.30 m/s     14.13 m/s     9.74 m/s     6.89 m/s

You have put a sonar device at the top of a frictionless inclined plane. That device allows you to measure the distance an object is from the device, as well as the speed and the acceleration of that object. If we decide that the origin (h = 0) is at the sonar device, we want to know what the height change is as we slide down the incline. For an angle below the horizontal of 9.74°, we see that our object has slid a distance 0.54 m, as measured along the incline itself. - Calculate the height change and report your answer as a negative number. (This value would be useful for calculating the change in gravitational potential energy, as we will do in the lab.) h=o e