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

Which of the following would not be a good fuse design?

a glass rod obtains a positive chartge from being rubbed by silk. Is this due to the glass gaining protons, or losing electrons?

2. A 60 N net force is applied to a 12 kg box. What is the acceleration of the box?

Is The neck is an example of a simple machine in the human body?

What is the kinetic energy of an object that has mass of 30 kilograms and move with a velocity of 20 m/s

How many earth years does it take mars to orbit the sun

Which represents a system that is almost completely closed?

If many household substances classify as acids or bases what is the ph scale

A protostar forms once the nebular cloud condenses and the core begins

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