1. A sound with a frequency of 261.6 Hz travels through water at a speed of 1435 m/s. What is the wavelength of the wave?
a. 1.83 x 10 -1 m
b. 3.753 x 10 5 m
c. 5.486 m
d. You cannot tell from the given information
2. A 23.0 kg mass of is accelerated at + 4.50 m/s2. What is the force acting on the mass?
a. 1.95 x 10 -1 N
b. +104 N
c. + 5.11 N
d. 225.4 N
3. A 72.34 kg skater accelerates to a stop with a force of - 34 .4N. What is the skater’s acceleration?
a. – 2.49 x 10-3 m/s2
b. + 2.49 x 10-3 m/s2
c. – 4.75 x 10-1 m/s2
d. 2.10 m/s2
4. In the absence of friction, the net force required to keep a 6.00-kg object moving with a constant velocity of 2.000 m/s is __ N.
a. 0.333 N
b. 2. 3 N
c. 12 N
d. No force is required to keep the object in motion.
5. If the net force acting upon an object is 0 N, then the object MUST ____.
a. be moving
b. be accelerating
c. be at rest
d. be moving with a constant speed in the same direction
e. Either c or d.
6. A desk is stationary in the room. A person tries to pushes on the desk to try to start it into motion. The desk does not move at all. The desk remains at rest because ______.
a. there is a force of static friction opposing its motion
b. there is an unbalanced force on the desk
c. there is a force of gravity opposing its motion
d. there are small dust bugs on the desk's feet which push back on the desk to keep it at rest
7. Newton assumed light consisted of particles. Which of the following properties of particles of light explains why light does not slow down when it is reflected?
a. They travel at very high speeds
b. They make elastic collisions
c. Each colour of light has a different very small mass
d. They are small compared to the spaces between them
e. They are affected by gravitational forces
8. A 5.770 kg object slides to the right along a surface with a co-efficient of friction of 0.404. The normal force is + 56.55 N. What is the force of friction?
a. - 22.85 N
b. -2.331 N
c. + 326.3 N
d. + 751 N
9. An apple is thrown into the air and is moving upwards and toward the right towards its peak. Assuming no air friction, the ball experiences a force which is _______
a. Directed upwards and to the right.
b. Directed downward and to the right.
c. Directed downward only.
d. Directed upward only.
10. A car horn produces a 5000 Hz sound. You hear the sound as 4700 Hz. Therefore the car is ___________.
a. moving towards you.
b. moving away from you.
c. is not moving.
d. There is not enough information about the car to decide.
It appears to me you are answer grazing.
1. To find the wavelength of the wave, we can use the formula:
wavelength = speed of sound / frequency
Given that the frequency is 261.6 Hz and the speed of sound in water is 1435 m/s, we can substitute these values into the formula:
wavelength = 1435 m/s / 261.6 Hz
Calculating this, we get:
wavelength =~ 5.486 m
Therefore, the answer is c. 5.486 m
1. To find the wavelength of a wave, you can use the formula:
wavelength = speed of wave / frequency of wave
In this case, the speed of sound in water is given as 1435 m/s, and the frequency of the sound is given as 261.6 Hz. Plugging these values into the formula, we get:
wavelength = 1435 m/s / 261.6 Hz
Calculating this, we find the wavelength to be approximately 5.486 m.
Therefore, the correct answer is option c. 5.486 m.
2. To find the force acting on an object, you can use Newton's second law of motion, which states:
force = mass x acceleration
In this case, the mass is given as 23.0 kg, and the acceleration is given as 4.50 m/s^2. Plugging these values into the formula, we get:
force = 23.0 kg x 4.50 m/s^2
Calculating this, we find the force to be approximately +104 N.
Therefore, the correct answer is option b. +104 N.
3. To find the acceleration of an object, you can use Newton's second law of motion again. Rearranging the formula, we get:
acceleration = force / mass
In this case, the force is given as -34.4 N and the mass is given as 72.34 kg. Plugging these values into the formula, we get:
acceleration = -34.4 N / 72.34 kg
Calculating this, we find the acceleration to be approximately -2.49 x 10^-3 m/s^2.
Therefore, the correct answer is option a. -2.49 x 10^-3 m/s^2.
4. In the absence of friction, the net force required to keep an object moving with a constant velocity is zero. So the correct answer is option d. No force is required to keep the object in motion.
5. If the net force acting upon an object is 0 N, then the object MUST be either at rest or moving with a constant speed in the same direction. Therefore, the correct answer is option e. Either c or d.
6. The desk remains at rest because there is a force of static friction opposing its motion. The force of static friction is a reaction force that prevents the desk from moving when there is an attempt to push it. Therefore, the correct answer is option a. There is a force of static friction opposing its motion.
7. Newton assumed light consisted of particles. The property of particles of light that explains why light does not slow down when it is reflected is that they are small compared to the spaces between them. When light reflects off a surface, it bounces off without interacting with the particles in the medium, leading to little to no slowing down of the light. Therefore, the correct answer is option d. They are small compared to the spaces between them.
8. To find the force of friction, you can use the formula:
force of friction = coefficient of friction x normal force
In this case, the coefficient of friction is given as 0.404, and the normal force is given as +56.55 N. Plugging these values into the formula, we get:
force of friction = 0.404 x 56.55 N
Calculating this, we find the force of friction to be approximately -22.85 N.
Therefore, the correct answer is option a. -22.85 N.
9. Since the apple is moving upwards and towards the right towards its peak, it is experiencing a force directed upwards and to the right. Therefore, the correct answer is option a. Directed upwards and to the right.
10. When a car is moving towards you, the sound waves it produces are compressed, resulting in a higher frequency. So if you hear the sound as 4700 Hz instead of the actual 5000 Hz, it means the car is moving towards you. Therefore, the correct answer is option a. moving towards you.