A burglar attempts to drag a 105 kg metal safe across a polished wood oor Assume that the coecient of static friction is 0.4, the coecient of kinetic friction is 0.3, and that the burglar can apply a pushing force of 520 N on the metal safe. What is the acceleration of the metal safe across oor?

Aplane travels 1000 miles in 5 hours .what is the planes average speed?

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?