Physics - Multiple Choice and Short Answer

1. The ratio of (1 kilogram/1 milligram) is
a) 10^2
b) 10^3
c) 10^6
d) 10^-3
e) 10^-6

2. The length of each side of a square is 4.0 m. What is the length of the diagonal of the square (shown as a dashed line in the figure)? 4.0 x 4.0
a) 2.8m
b) 3.5m
c) 5.7m
d) 8.0m
e) 16m

3. Which statement is true concerning scalar quantities?
a) Scalar quantities must be represented by base units.
b) Scalar quantities have both magnitude and direction.
c) Scalar quantities can be added to vector quantities using rules of trigonometry.
d) Scalar quantities can be added to other scalar quantities using rules of trigonometry.
e) Scalar quantities can be added to other scalar quantities using rules of ordinary addition.

4. Jamie's hair grows with an average speed of 3.5 x 10^-9 m/s. How long does
it take for her hair to grow 0.3 m? Note: 1 year = 3.156 x 10^7 s.
a) 1.9 yr
b) l.3 yr
c) 0.37 yr
d) 5.4 yr
e) 2.7 yr

5. An object moving along a straight line is decelerating. Which one of the following statements concerning the object's acceleration is necessarily true?
a) The value of the acceleration is positive.
b) The direction of the acceleration is in the same direction as the displacement.
c) An object that is decelerating has a negative acceleration.
d) The direction of the acceleration is in the direction opposite to that of the velocity.
e) The acceleration changes as the object moves along the line.

6. A projectile is fired at an angle of 60.0° above the horizontal with an initial speed of 30 m/s. How long does it take the projectile to reach the highest point in its trajectory?
a) 1.5s
b) 2.7s
c)4.0s
d)6.2s
e)9.8s

7. A crate with a weight of 225 N accelerates along a frictionless surface as
the crate is pulled with a force of F = 14.5 N as shown in the drawing.
What is the horizontal acceleration of the crate?
a) 1.4m/s2
b) 0.427 m/s2
c) 1.29 m/s2
d) O.597m/s2
e) 0.644 m/s2

8. A 2400 kg satellite is in a circular orbit around a planet. The satellite travels with a constant speed of 6.67 x 10^3 m/s. The radius of the circular orbit is 8.92 x 10^6 m. Determine the magnitude of the gravitational force exerted on the satellite by the planet.
a) 1.2 x 104 N
b) 2.4 x 1O4 N
c) 5.0x103 N
d) 7.5 x 10^-4
e) This cannot be determined since the mass and radius of the planet are not given.

9. A rock is suspended from a string and moves downward at constant speed. Which statement is true concerning the tension in the string if air resistance is ignored?
a) The tension is zero.
b) The tension points downward.
c) The tension is equal to the weight of the rock.
d) The tension is less than the weight of the rock.
e) The tension is greater than the weight of the rock.

10. A wheel, originally rotating at 126 rad/s undergoes a constant angular deceleration of 5.00 rad/s2. What is its angular speed after it has turned through an angle of 628 radians?
a) 15 rad/s
b) 19 rad/s
c) 98 rad/s
d) 121 rad/s
e) 150 rad/s

Short Essay Answers:

1. Is it possible for an object to have a negative acceleration while increasing in speed? If so, provide an example.

2. Whiplash sometimes results from an automobile accident when the victim's car is struck from behind. Explain why the head of the victim seems to be thrown backward. Is it really?

3. Does a skydiver exert a gravitational force on the Earth? If so, how much?

4. A bug climbs onto a record player and the turntable begins to rotate. Where on the record would the bug be able to stay on the easiest? Why?

Problems (show work)

1. A frog jumps into the air vertically and lands back on its lilypad after 1.5 s. With what speed did it jump into the air and to what height did it reach?
2. A crate slides down a ramp that is at a 30° incline. The speed of the crate at the bottom would have been 3 times greater if there was no friction present. What is the coefficient of friction between the crate and the ramp?

3. A marble falls out of a child's pocket and rolls 5 meters before it falls down a drain. If it made 60 revolutions during this distance, what is the distance, what is the diameter of the marble?

4. A ball is projected with an initial speed of 30 m/s at an angle of 53° above the horizontal.
a) Find the distance the ball travels horizontally.
b) Find the maximum height of the ball during the flight.