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PhysicsNovice
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Thanks to everyone who have viewed my threads and helped me understand some basic physics concepts better. I passed my first on-line certification on a basic physics module. I am now proceeding to Module 2. I have complete the first section and I am working on the assessment questions. My answers are marked with an astericks. Please review for me and let me know the one that I got correct. Those that I missed please provide some information to get me thinking in the right direction. Thanks again. I am starting ot enjoy this work.
1. Imagine riding a glass-walled elevator that goes up the outside of a tall building at a constant speed of 20 meters per second. Assuming that you drop a ball as you pass a window washer, the window washer will see the ball:
a. fall starting from rest
b. fall starting with an upward speed of 20 m/s*
c. fall starting with a downward speed of 20 m/s
d. remain stationary
2. You can throw a ball vertically up in a car moving with a constant velocity and have it land back in your hand because:
a. there ins no net horizontal force acting on the ball
b. the reference system attached to the car is non-inertial*
c. there is net force in the forward direction
d. the force in the forward direction is canceled by the inertial force
3. An observer drops a ball in a train traveling along a straight, horizontal track with a constant acceleration in the forward direction. What would an observer in the train say about the horizontal force acting on the ball?
a. There is not horizontal force*
b. A force acts backward
c. A force acts forward
d. There is a centrifugal force
4. An elevator is being accelerated upward with an acceleration equal to one-half that of gravity. If a man who weighs 160 lbs, when he is at rest on the earth, steps on a bathroom scale in the elevator, the reading will be:
a. zero
b. 80 lbs
c. 160 lbs*
d. 240 lbs
5. Which of the following was NOT cited as evidence that the Earth moves?
a. The plane of pendulum rotates
b. The sun rises and sets each day*
c. Hurricanes turn counterclockwise in the Northern Hemisphere; clockwise in the Southern
d. The stars exhibit parallax
6. As a spaceship approaches you in outer space at 50% of the speed of light, its rotating beacon sends out a pulse of light. An observer in the ship measures the speed of the light leaving the ship to be
a. 50 % of c*
b. 75 % of c
c. equal to c
d. 150 % of c
7. As a friend passed you at a very high speed, she reported that she simultaneously exploded a firecracker at each end of her skateboard. Which one exploded first from your point of view?
a. the one at the front
b. the one at the back*
c. they exploded simultaneously
d. the answer depends on the speed of the skateboard
8. Suppose a meterstick zips by you at a speed only slightly less than the speed of light. If you measure the length of the meterstick as it goes by, you would determine that it is ____________ one meter long.
a. shorter than
b. longer than
c. still*
d. The answer depends on the speed of meterstick
9. Suppose two teams of astronauts who think they are accelerating through space are actually sitting on the surfaces of Earth and Mercury. The gravitational field of Mercury is much smaller than that of Earth. Which team thinks it has the larger acceleration?
a. Mercury
b. Earth
c. The accelerations are the same*
d. Neither team can determine their acceleration
10. The general theory of relativity says that clocks run ________ as the gravitational force is increased.
a. at the same rate
b. slower*
c. faster
1. Imagine riding a glass-walled elevator that goes up the outside of a tall building at a constant speed of 20 meters per second. Assuming that you drop a ball as you pass a window washer, the window washer will see the ball:
a. fall starting from rest
b. fall starting with an upward speed of 20 m/s*
c. fall starting with a downward speed of 20 m/s
d. remain stationary
2. You can throw a ball vertically up in a car moving with a constant velocity and have it land back in your hand because:
a. there ins no net horizontal force acting on the ball
b. the reference system attached to the car is non-inertial*
c. there is net force in the forward direction
d. the force in the forward direction is canceled by the inertial force
3. An observer drops a ball in a train traveling along a straight, horizontal track with a constant acceleration in the forward direction. What would an observer in the train say about the horizontal force acting on the ball?
a. There is not horizontal force*
b. A force acts backward
c. A force acts forward
d. There is a centrifugal force
4. An elevator is being accelerated upward with an acceleration equal to one-half that of gravity. If a man who weighs 160 lbs, when he is at rest on the earth, steps on a bathroom scale in the elevator, the reading will be:
a. zero
b. 80 lbs
c. 160 lbs*
d. 240 lbs
5. Which of the following was NOT cited as evidence that the Earth moves?
a. The plane of pendulum rotates
b. The sun rises and sets each day*
c. Hurricanes turn counterclockwise in the Northern Hemisphere; clockwise in the Southern
d. The stars exhibit parallax
6. As a spaceship approaches you in outer space at 50% of the speed of light, its rotating beacon sends out a pulse of light. An observer in the ship measures the speed of the light leaving the ship to be
a. 50 % of c*
b. 75 % of c
c. equal to c
d. 150 % of c
7. As a friend passed you at a very high speed, she reported that she simultaneously exploded a firecracker at each end of her skateboard. Which one exploded first from your point of view?
a. the one at the front
b. the one at the back*
c. they exploded simultaneously
d. the answer depends on the speed of the skateboard
8. Suppose a meterstick zips by you at a speed only slightly less than the speed of light. If you measure the length of the meterstick as it goes by, you would determine that it is ____________ one meter long.
a. shorter than
b. longer than
c. still*
d. The answer depends on the speed of meterstick
9. Suppose two teams of astronauts who think they are accelerating through space are actually sitting on the surfaces of Earth and Mercury. The gravitational field of Mercury is much smaller than that of Earth. Which team thinks it has the larger acceleration?
a. Mercury
b. Earth
c. The accelerations are the same*
d. Neither team can determine their acceleration
10. The general theory of relativity says that clocks run ________ as the gravitational force is increased.
a. at the same rate
b. slower*
c. faster