Which device is used to increase or decrease the voltage of an alternating

current?

O

A. A commutator

O

B. A generator

O c. A motor

O

D. A transformer

describe the difference between a physical and a chemical change and explain what happens during a chemical reaction

Why is Earth a troubled planet? A. because the Dark Thing came to Earth many years ago. B. because Earth has too many people fighting the Dark Thing C. because people on Earth don't know how to think for themselves D. because there is evil on Earth

What is the mode of heat transfer from drying of wet hot plate in atmosphere

A subwoofer needs a household voltage of 110V to push a current of 5.5 A through its cool. What is the resistance of the subwoofer

A block of mass m=1.2 kg is held at rest against a spring with a force constant k=730N/m. Initially the spring is compressed a distance d.

How do whales bats and dolphins use echolocation? A To scare away predators B To attract mates C To orient them selves and find food D To tell animals of there species where they are

How much force would be needed to move a car with the mass of 100kg to an acceleration of 5m/s/s?

A pendulum bob is made from a sphere filled with water. What would happen to the frequency of vibration of this pendulum if the sphere had a hole in it that allowed the water to leak out slowly?

Elias serves a volleyball at a velocity of 16 m/s. The mass of the volleyball is 0.27 kg. What is the height of the volleyball above the gym floor when its total mechanical energy is 41.70 J? Round to the nearest number.

Which of the following is the best description of a graph? A. Equations that can be plotted B. A representation of an equation C. Independent and dependent variables D. x and y lines