A high diver steps off a diving platform that is 10 meters above the water. If no air resistance is present, during the fall there will be a decrease in the diver's
gravitational potential energy
total mechanical energy
kinetic energy
momentum
Which of the following is a best example of work being done on an object?
lifting a 50 kg weight up off the ground
holding a bag of groceries
keeping a board in place
pushing a car that will not move
What is the kinetic energy of a 2 kg toy car that is moving with a velocity of 5 m/s
5 J
10 J
25 J
50 J
A hydraulic lift used at an automotive repair shop raises a 1000 kg car two meters off the ground. What is the potential energy given to the car.
1000 J
2000 J
9800 J
19,600 J
A rock climber weighs 550 N and is carrying a backpack that weights 50 N. How much total work has been done after she climbs 12 m.
50 J
600 J
6000 J
7200 J
Fireworks displays are common on the 4th of July. Energy changes occur during the flight of a firework. Which of the following represents a correct energy change?
When the firework rocket left the ground chemical energy changed into kinetic energy.
When the firework rocket exploded kinetic energy changed into chemical potential energy.
During the rise of the firework rocket gravitational potential energy changed into kinetic energy.
During the rise of the firework rocket gravitational potential energy changed into heat, light, and sound.
A skateboarder travels from location 1 to location 4 as shown below.
At which location does the skateboarder have the most kinetic energy and the least potential energy?
1
2
3
4
Three different boxes are lifted to different heights.
Box X weighs 115 N and is lifted tp 15 m.
Box Y weighs 210 N and is lifted to 10 m.
Boz Z weighs 305 N and is lifted to 5 m.
Which of the following statements best describes the boxes' change in mechanical energy?
Box X has the greatest change in mechanical energy.
Box Z has the smallest change in mechanical energy.
Boxes X and Y have the same change in mechanical energy.
Boxes Y and Z have the same change in mechanical energy
Windmills are used to covert wind energy into a more useful form. In most cases, there are three steps in this process. The energy is in a different form at each step. Which of the following flowcharts shows the most likely order of the energy change?
wind energy → mechanical energy → solar energy
wind energy → thermal energy → mechanical energy
wind energy → solar energy → electrical energy
wind energy → mechanical energy → electrical energy
The diagram shows two bowling balls of equal mass. Ball A is resting near the edge of a shelf. Ball B is resting on the ground below.
Which of the following statements best describes the diagram above?
Ball A has more kinetic energy than Ball B.
Ball B has more kinetic energy than Ball A.
Ball A has more potential energy than Ball B.
Ball B has more potential energy than Ball A.
Which statement best explains how iron can become a magnet?
Electrons are easily removed,
Electrons spin in a unique direction.
Atoms have smaller nuclei.
Atoms are strongly bonded together.
Two parallel copper wires are each carrying the same electrical current in the same direction. Which statement explains how they respond to each other?
They strengthen each other, because they have opposite magnetic fields.
They strengthen each other, because they have similar magnetic fields.
They repel each other, because they have opposite magnetic fields.
They repel each other, because they have similar magnetic fields.
The diagram below shows an object made from a battery, a nail, and some wire.
What will happen if you touch a metal paperclip to the nail?
The paperclip will stick to the nail.
The wires will melt.
The nail will give you a shock.
The battery will spark.
Which of the following electromagnets would have the greatest magnetic fi eld?
The diagram below shows a bar magnet within a coil of conducting wire. The magnet is moved back and forth. The magnet never has contact with the wire.
As the magnet is moved, the wire will
have an electric current.
become negatively charged.
decrease in temperature.
demagnetize the bar magnet.
The diagram below shows current flow through a wire.
Which of the following represents the magnetic field resulting from the current?
The diagram pictured shows a loop of wire being rotated at a constant rate about an axis in a uniform magnetic fi eld.
As the speed of rotation of the wire loop is increased, the maximum voltage induced in the loop
decreases
increases
remains the same
What is the main advantage of using alternating current (AC) over direct current (DC) when transmitting electricity?
AC is not affected by the use of transformers, but the use of DC requires transformers.
AC power lines need less insulation than DC power lines.
AC has fewer power surge problems than DC
AC makes it easier to step voltage up or down with transformers, as compared to DC.
The primary coil of a transformer has 400 turns; the secondary coil has 1,000 turns. An alternating current is sent through the primary coil. The voltage in the primary coil has an amplitude of 17 V. Which statement best describes the voltage amplitude in the secondary coil?
between 0 V and 17 V, because the coils form a step-down transformer
between 17 V and 50 V, because the coils form a step-up transformer
between 17 V and 50 V, because transformer coils are conductors
between 0 V and 17 V, because transformer coils are insulators
The diagram shows a wire loop rotating between magnetic poles. During 360 degrees of rotation from the position shown, the induced voltage changes in