the useful power out of an electric motor is 20w and the total power into the motor is 80w calculate the percentage efficiency of the motor

Assuming a successful launch, what is the speed of the small CO2 rocket given that it travels about 10 meters in about 3 seconds?

As the current in a coil of wire increased, the magnetic field strength what?

A pencil has a mass of 35g. What is the pencil's weight in Newtons?

What will happen when a ball rolls down a hill?

What is the relationship between temperature and density? What is the relationship between temperature and density? In general, warmer materials are less massive, and therefore less dense, and colder materials are more massive.

A basketball player, who weighs 600 newtons, jump 0.5 meters vertically off the floor. Calculate her kinetic energy just before hitting the floor. a) 300J b) 3000J c) 9.81m/s^2 d) 0

What are three physical properties of helium

Why is the calorimeter assembled by placing one cup inside the other?

The current through two identical light bulbs connected in a series is 0.25 amps. The voltage across both bulbs is 100 volts. Find the resistance of a single light bulb.

The Sun transfers light energy that is transformed into what kind of energy in plants?