## Pages

### A flying mosquito hits the windshield of a moving car and gets smashed, but the car is intact. which of the following statements is correct?

A: The force on the mosquito by the car has the same magnitude as the force on the car by the mosquito.
B: The force on the mosquito by the car is much larger than the force on the car by the mosquito because the car is moving.
C: The force on the mosquito by the car is much larger than the force on the car by the mosquito, therefore the mosquito gets smashed but the car is intact.
D: The force on the mosquito by the car is much larger than the force on the car by the mosquito because the car is much heavier than the mosquito.

Show or Reveal the Answer

The force on the mosquito by the car is much larger than the force on the car by the mosquito, therefore the mosquito gets smashed but the car is intact.

### Recall the portion of the video in which the girl pushes her brother on the sled at constant velocity. The pushing force she exerts on the sled is _____ the frictional force the ground exerts on the sled.

A: less than
B: equal to
C: greater than

Show or Reveal the Answer

equal to

### While driving fast around a sharp right turn, you find yourself pressing against the car door. What is happening?

A: Centrifugal force is pushing you into the door.
B: The door is exerting a rightward force on you.
C: Both of the above.
D: Neither of the above.

Show or Reveal the Answer

The door is exerting a rightward force on you.

### In an electromagnetic wave in free space, the electric and magnetic fields are

A: parallel to one another and perpendicular to the direction of wave propagation.
B: parallel to one another and parallel to the direction of wave propagation.
C: perpendicular to one another and perpendicular to the direction of wave propagation.
D: perpendicular to one another and parallel to the direction of wave propagation.

Show or Reveal the Answer

perpendicular to one another and perpendicular to the direction of wave propagation.

### Electromagnetic waves are transverse waves.

A: True
B: False

Show or Reveal the Answer

True

as both electric and magnetic field vibrate in direction perpendicular to the propagation of the wave.

### In an electromagnetic wave in free space, the electric and magnetic fields are in phase.

A: True
B: False

Show or Reveal the Answer

True

in an electromagnetic wave in free space the electric and magnetic fields are perpendicular

### In an electromagnetic wave in free space, the electric and magnetic field vectors E and B are equal in magnitude.

A: True
B: False

Show or Reveal the Answer

False

they are not necessarily equal

### In an electromagnetic wave in free space, the electric and magnetic energy densities are equal.

A: True
B: False

Show or Reveal the Answer

True