When two charged particles are moving toward each other, their velocities decrease until they eventually come to a stop. What happens afterward?(1 point)

Question

Responses

They accelerate toward each other.
They accelerate toward each other.

They bond and accelerate together.
They bond and accelerate together.

They accelerate in opposite directions.
They accelerate in opposite directions.

They remain in the same place without moving.

A bar magnet is held in place while another bar magnet is placed near it. The second bar magnet spins around and attaches to the first magnet on one end. Which statement is correct about the energy stored in the magnetic field? (1 point)
Responses

The increase in the energy stored in the system is proportional to the decrease in kinetic energy.
The increase in the energy stored in the system is proportional to the decrease in kinetic energy.

The decrease in the energy stored in the system is proportional to the decrease in kinetic energy.
The decrease in the energy stored in the system is proportional to the decrease in kinetic energy.

The decrease in the energy stored in the system is proportional to the increase in kinetic energy.
The decrease in the energy stored in the system is proportional to the increase in kinetic energy.

The increase in the energy stored in the system is proportional to the increase in kinetic energy.

Which of the following factors would decrease the magnetic field strength of an electromagnet?(1 point)
Responses

increasing the current or using a higher-voltage power source
increasing the current or using a higher-voltage power source

increasing the number of turns in the coil of wire
increasing the number of turns in the coil of wire

increasing the distances between the turns of the coil
increasing the distances between the turns of the coil

using an iron core or nail

Two astronauts conduct a space walk. One of them produces a sound and also turns on a flashlight. What will the other astronaut perceive?(1 point)
Responses

The other astronaut will neither hear the sound nor see the light.
The other astronaut will neither hear the sound nor see the light.

The other astronaut will hear the sound and see the light.
The other astronaut will hear the sound and see the light.

The other astronaut will hear the sound but will not see the light.
The other astronaut will hear the sound but will not see the light.

The other astronaut will not hear the sound but will see the light.

How are radio dishes able to detect electromagnetic waves?(1 point)
Responses

The waves cause the antenna to become magnetized.
The waves cause the antenna to become magnetized.

The waves produce a charge in the antenna.
The waves produce a charge in the antenna.

The waves cause magnets to vibrate in the antenna.
The waves cause magnets to vibrate in the antenna.

The waves cause charges to oscillate in the antenna.

What happens to sound waves from an object as it moves toward you?(1 point)
Responses

The pitch gets lower because of an increase in frequency.
The pitch gets lower because of an increase in frequency.

The pitch gets lower because of an increase in wavelength.
The pitch gets lower because of an increase in wavelength.

The pitch gets higher because of an increase in wavelength.
The pitch gets higher because of an increase in wavelength.

The pitch gets higher because of an increase in frequency.

When a string is plucked, like a string on a guitar, why do other frequencies of sound result?(1 point)
Responses

Parts of the string are near different materials, which cause different frequencies.
Parts of the string are near different materials, which cause different frequencies.

The hand or pick that plucked the string also vibrates, creating the other frequencies.
The hand or pick that plucked the string also vibrates, creating the other frequencies.

Fractions of the wire also vibrate at different frequencies than the whole string.
Fractions of the wire also vibrate at different frequencies than the whole string.

The density of air around the string is different in different areas, resulting in different frequencies.

Which combination of frequencies would produce the lowest beat frequency?(1 point)
Responses

500 Hz and 600 Hz
500 Hz and 600 Hz

10 Hz and 15 Hz
10 Hz and 15 Hz

10 Hz and 20 Hz
10 Hz and 20 Hz

500 Hz and 501 Hz

A sound has a higher pitch than a bell. Which quantity must also be higher in this sound than in the bell?(1 point)
Responses

wavelength
wavelength

speed
speed

amplitude
amplitude

frequency

If you were to calculate the wavelength of a sound wave with a frequency of 220 Hz that is traveling through water, what one quantity would you need to know to find the wavelength?(1 point)
Responses

the distance to the observer of the sound
the distance to the observer of the sound

the speed of sound in water
the speed of sound in water

the direction that the wave is heading
the direction that the wave is heading

the intensity of the sound

Answer 1

Here are the correct responses to your questions:

1. When two charged particles are moving toward each other, their velocities decrease until they eventually come to a stop. What happens afterward?

   • They bond and accelerate together. (This assumes they are oppositely charged and attract each other.)

2. Which statement is correct about the energy stored in the magnetic field?

   • The increase in the energy stored in the system is proportional to the decrease in kinetic energy.

3. Which of the following factors would decrease the magnetic field strength of an electromagnet?

   • increasing the distances between the turns of the coil.

4. Two astronauts conduct a space walk. One of them produces a sound and also turns on a flashlight. What will the other astronaut perceive?

   • The other astronaut will not hear the sound but will see the light. (Sound cannot travel in the vacuum of space, but light can.)

5. How are radio dishes able to detect electromagnetic waves?

   • The waves cause charges to oscillate in the antenna.

6. What happens to sound waves from an object as it moves toward you?

   • The pitch gets higher because of an increase in frequency. (This is known as the Doppler effect.)

7. When a string is plucked, like a string on a guitar, why do other frequencies of sound result?

   • Fractions of the wire also vibrate at different frequencies than the whole string.

8. Which combination of frequencies would produce the lowest beat frequency?

   • 500 Hz and 501 Hz (The beat frequency is the difference between the two frequencies, which is 1 Hz.)

9. A sound has a higher pitch than a bell. Which quantity must also be higher in this sound than in the bell?

   • frequency.

10. If you were to calculate the wavelength of a sound wave with a frequency of 220 Hz that is traveling through water, what one quantity would you need to know to find the wavelength?

    • the speed of sound in water. (Wavelength can be calculated using the formula: wavelength = speed of sound / frequency.)