A piano mover raises a 1000-n piano at a constant speed using a very light rope in a frictionless pulley system, as shown in the figure. with what force is the mover pulling down on the rope?

A ball is thrown into the air with 100 J of kinetic energy, which is transformed to gravitational potential energy at the top of its trajectory. If it returns to its original level less than 100 J of kinetic energy, the ball encountered a.

A Carnot refrigerator is operated between two heat reservoirs at temperatures of 320 K and 270 K. (a) If in each cycle the refrigerator receives 415 J of heat energy from the reservoir at 270 K, how many joules of heat energy does it deliver to the

If the fuel he carries produces 36 kJ of heat per gram when it burns, how much fuel should he carry? (For the sake of simplicity, assume that the transfer of heat is 100 %% efficient.)

4. A metal of mass 1.55kg was heated from 300K to 320K in 6 minutes by a boiling ring of 85 W rating, calculate the specific heat capacity of the metal. {Neglect heat losses to the surrounding.}

Explain the difference between mass and weight and how they are measured.

What does Kepler's second law state? A. Planets travel in ellipses. B. Planets sweep equal areas in equal times. C. A planet's apparent backward movement is termed retrograde motion. D.

Why do charges build up in a cloud

How does the wave model of electrons orbiting the nucleus account for discrete energy values?

An ecosystem is all the populations of organisms that live together and A. the microorganisms that depend on them. B. the organisms that generate energy from sunlight. C. the physical factors with which they interact. D.

Which statement about magnetic poles is accurate? A) Same magnetic poles attract, while different magnetic poles repel. B) Same magnetic poles attract, while different magnetic poles attract.