Other Physics Answers

The Bob of a large pendulum has a mass of 30kg. The change in height of the pendulum as it swings is 0.5m. A. Calculate the changes in GPE as the Bob moves from its highest to its lowest point. B. All the GPE stored in the Bob at its highest point is transferred to kinetic energy as the Bob reaches its lowest point. Calculate the maximum speed of the bob.

The current theory of the structure of the Earth, called plate tectonics, tells us that the continents are in constant motion. Assume that the North American continent can be represented by a slab of rock 4850 km on a side and 38 km deep and that the rock has an average mass density of 2650 kg/m3. The continent is moving at the rate of about 3.6 cm/year. What is the mass of the continent? Answer in units of kg. Don't round answer.

This question is typical on some driver’s license exams: A car moving at 40 km/h skids 15 m with locked brakes. How far will the car skid with locked brakes at 100 km/h? Assume that energy loss is due only to sliding friction. Answer in units of m. Don't round answer

A crate is pulled by a force (parallel to the incline) up a rough incline. The crate has an initial speed shown in the figure below. The crate is pulled a distance of 7.99 m on the incline by a 150 N force. The acceleration of gravity is 9.8 m/s2. a) What is the change in kinetic energy of the crate? Answer in units of J. Don't round answer.

A cheerleader lifts his 52.7 kg partner straight up off the ground a distance of 0.858 m before releasing her. Assume the partner’s velocity is zero at the beginning and the end of the lift. The acceleration of gravity is 9.8 m/s2. If he does this 13 times, how much work has he done? Answer in units of J. Don't Round answer.