General Physics I
Final Exam Primer
1. The standard kilogram is a platinum-iridium cylinder 39-mm in height and 39mm in diameter.† What is the density of the material?
___1. 21.0 N
___2. 20 g/ cm 3
___3.† 21464 kg / m3
___4.† 5366 kg / m3
2. A temperature of 88 degrees Fahrenheit is equivalent to how many Celsius degrees?
3.† †A weight lifter can lift a 400-lb. barbell over his head and hold it there for 3 seconds before setting it down. The net work that he has done
___1. depends on the weight of the barbell.
___2. depends on the time that the weight was held.
___4.is equal to zero.
4. A man pushes a 100-kg crate across a horizontal floor. The work done
by gravity on the load
___ 1. depends on the weight of the load.
___ 2. cannot be calculated without more information.
___ 3. is equal to zero.
___4. 1960 joules
5. A man pushes a 200-kg crate 50 meters across a horizontal floor in 25 seconds.† The work done by the man on the load is
___ 1800 joules.
___ 2. Is equal to zero
___ 3. 1600 joules.
___ 4. 98000 joules
___ 5. Cannot be calculated.
6. Is it possible for an objectís instantaneous velocity and instantaneous acceleration to be of opposite sign at the same moment in time?
___ 1. yes
___ 2. no
___ 3. need more information
7. A disk is rotating at a constant rate about a vertical axis through its center.
Point Q is twice as far from the center of the disk as point P is. The angular
velocity of Q at a given time is
___ 1. twice as big as Pís.
___ 2. the same as Pís.
___ 3. half as big as Pís.
___ 4. none of the above.
8. Sum the following vectors and express† the sum in polar (R,q) form.
A =††††† 12† x† +†† 15† y
C =†††† †††5† x† +† -5† y
D =†† - 30† x†† +† 17† y
E = (15 , 30o)
9. A tower has dimensions of† length = 3.28 ft, width =1574.80 in, depth = 9.8425 yards. What is its total volume?† Express your answer in SI units.
10.† †The distance of one lap around a circular dirt bike track is 1.25 km. A rider moving counterclockwise at constant speed completes a lap in 1.8 minutes.† What is his angular velocity?† What is the magnitude of his tangential velocity?
11.† A 3-kg mass rests on a plane inclined at an angle of 30į as shown and has a coefficient of static friction ĶS = 0.4.
a. What is the largest mass m2 that can be attached to the string passing over the pulley without causing the mass m1 to move ? b. If the mass m2 is changed to 5 kg and the 3kg block accelerates up the plane with a = 3.3 m/s2, what is the coefficient of kinetic friction mk?
12. A 2500-kg car moving east at 24 m/s collides with a 3200-kg car moving north at 14 m/s.† The cars stick together after the collision.
a. Find the velocity (magnitude and direction) of the cars at the moment of impact.
b. The cars slide to a halt over a distance of 15 meters.† What is the coefficient of kinetic friction of the road?† What is the work done by friction?
†13. A hot air balloon floats motionless at 0.33 km above the ground. A sandbag is released, and the balloon rises with constant acceleration of 0.330 m/s2. How long does it take for the sandbag to fall to earth?† What is its velocity just as it strikes the ground? How high is the balloon at the moment the sandbag strikes the ground?† (show your work)
14.† A 25 gram projectile is shot from a spring loaded gun .The spring is compressed 6 cm.† The projectile strikes and embeds itself in a pendulum bob that is 200 grams .† After the collision the bob and bullet reach a maximum height of 16 centimeters.† Determine the spring constant , K, of the spring gun (cite appropriate units).†††
15.† The pendulum described in question 14 has a length of 16 cm from pivot to the bob.† What is the angular velocity of the bob at the instant the bullet strikes?† What is the maximum angle from vertical that the pendulum attains?