How to find mechanical advantage

Which best term to describe a chemical reaction that absorbs energy from its surroundings? A. thermal conductor B. thermal insulator C. Endothermic D. exothermic

How many significant figures does 1.362 + 25.2 have?

The active element of a certain laser is made of a glass rod 31.0 cm long and 1.30 cm in diameter. Assume the average coefficient of linear expansion of the glass is equal to 9.00 10-6 (°C) - 1. The temperature of the rod increases by 62.0°C.

How do things rust? Is this chemical or mechanical weathering?

By what factor does the energy of a 1-nm x-ray photon exceed that of a 10-mhz radio photon

A ballet student with her arms and a leg extended spins with an initial rotational speed of 0.90rev/s. As she draws her arms and leg in toward her body, her rotational inertia becomes 0.80 kg⋅m2 and her rotational velocity is 4.1rev/s.

The power rating of a vacuum cleaner is 0.8 kilowatts. If you use the vacuum cleaner for 2.5 hours, how much energy does it use?

Which has more gravitational potential energy - - a cliff diver at the top of the cliff or a cliff diver at the bottom of the cliff?

A skydiver with a mass of 60 kg jumps from an airplane. Five seconds after jumping the force of air resistance is 300 N. What is the acceleration of the sky diver, five seconds after jumping?

How many basic wave forms are there? A.) 1 B.) 2 C.) 3 D.) 4