A transformer has a primary voltage of 480 volts and a secondary voltage of 120 volts. if the primary windings have 700 turns, how many turns are in the secondary windings? (voltage and number of turns are directly proportional.)

Which of the following is an example of Newton's first law of motion? Sam's bike hits a curb and he flies over the handlebars, onto the grass. A feather and a brick are dropped from a ladder. The brick exerts a greater force when it hits the ground.

Two strips of material, A and B, are identical, except that they have emissivities of 0.4 and 0.6, respectively. The strips are heated to the same temperature and have a red glow.

Which of the following energy sources is in no way derived from the Sun? A) nuclear energy B) tidal energy C) wind energy D) petroleum

How does the electric force between two charged particles change if the distance between them is increased by a factor of 2? a. it is decreases by a factor of 2 b. it is increases by a factor of 2 c. it is increases by a factor of 4 d.

A wave travels along a stretched horizontal rope. The vertical distance from crest to the trough for this wave is 11 cm and the horizontal distance from crest to trough is 21 cm.

A 35-N bucket of water is lifted vertically 3.0 m and then returned to its original position. How much work did gravity do on the bucket during this process?

You then decide to throw another disc to your friend in the tree for fun. If you throw the disc at a speed of 10 m/s and your friend catches it 5.0 m above you, what was the speed of the disc just before your friend catches it

Which is true? An ideal emf device has internal resistance and a real emf device does not. A real emf device sets up a potential difference and an ideal emf device does not.

An object is released from rest on a planetthat has no atmosphere. The object fallsfreely for 2.03 m in the first second. What is the magnitude of the accelerationdue to gravity on the planet?

Properties of elements within a ... on the periodic table change in a predictable way from one side of the table to the other