The elevator of a large building is to raise a net mass of 400 kg at a constant speed of 12 m/s using an electric motor. minimum power rating of the motor should be

A thread holds a 1.5-kg and a 4.50-kg cart together. After the thread is burned, a compressed spring pushes the carts apart, giving the 1.5 kg cart a speed of 26 cm/s to the left. What is the velocity of the 4.5-kg cart? a. 10 cm/s b. 4.56 cm/s c. 8.

Which electromagnetic wave has the highest frequency?

A toy car with a mass of 2kg starts at rest. A spring performs 196 joules of work on the car. What is the toy cars final velocity

The relationship between total energy and kinetic energy and potential energy is

What is role of gravity in our daily life?

A substance has a density of 13.5 g/cm3. What is the volume of a 50 g block of this substance?

Select all of the answers that apply. Which statements are true regarding the scientific evidence supporting the big bang theory? Researchers found cosmic microwave background radiation, which is a heat imprint left over from the big bang.

How are magnetic poles and electrical charges similar? A. Their same forces repel each other, and their opposite forces attract each other. B. Their same forces attract each other, and their opposite forces repel each other. C.

As part of his meal, a workman has a cup containing a hot drink. In order to keep the drink hot whilst he eats the rest of his meal, he covers the cup, as shown in the figure. Which sources of energy loss does this action reduce? Tick two boxes.

When energy is transformed, the amount of usable energy?