Download South Pasadena • Physics Name 5 · Applications of Forces Period

South Pasadena • Physics
Name
5 · Applications of Forces
Period
Date
REVIEW PACKET
Station 1-Circular Motion
1. A ball is swung around counterclockwise (toward the left) by a rope in a circle. Draw the vectors for the
velocity, acceleration, and force in the motion.
2. Finnish Fling is a small ride located in Scandinavia. Guests are left stuck to the wall of the ride by
“centrifugal force,” while the floor is then dropped from beneath their feet. Explain why this is happens.
Station 2-Circular Motion
1. An 0.65-kg ball connected to a string is swung horizontally in a circle with a radius of 1.5 m. It makes five
revolutions every 15 seconds.
a. Find the frequency.
b. Find the velocity.
c. Find the acceleration.
d. Find the force of the tension on the string.
2. A stopper attached to a string is swung horizontally.
a. If the tension on the string is maintained, what happens to the velocity if the radius is doubled?
b. If the tension on the string is doubled, but the radius stays the same, how does the velocity change?
Station 3- Gravition
1. The moon makes a near-circular orbit around the earth. Explain why Newton’s First Law does not apply (i.e.
an object in motion stays in motion in a straight line …). Use your knowledge of Newton’s Law of Universal
Gravitation in your explanation.
Station 4-Gravitation
1. A 63.0-kg person is 3.45 m away from a 15.0-kg box.
a. What is the force of gravitation between the person and the box?
b. How would the force change if the person was twice as far away? (Explain; do not calculate.)
c. How would the force change is the person weighed half as much? (Explain; do not calculate.)
2. Mars has a mass of 6.4191 × 1023 kg. It has a radius of 3396 km.
a. How much would a 50-kg person weigh on Mars?
b. What is the acceleration due to gravity on Mars?
Station 5-Friction
1. Circle the correct relationship:
a. The coefficient of static friction is [ greater than | the same as | less than ] the coefficient of kinetic
friction.
b. The friction of an object with a larger mass is [ greater than | the same as | less than ] that of an object
with a smaller mass.
c. A rougher surface has [ a larger | the same | a smaller ] coefficient than a smoother surface.
d. The coefficient of friction on a given surface of a heavier object is
[ greater than | the same as | less than ] that of a lighter object.
e. The friction of an object with greater surface is [ greater than | the same as | less than ] the friction of
another object (with the same mass) with smaller surface area.
2. Explain the difference between static and kinetic friction. Also explain how the coefficients of static and
kinetic friction differ.
Station 6-Friction
1. A 5.0-kg object is pushed with a constant force of 15 N. Find the coefficient of kinetic friction for this surface.
2. A 5.0-kg object is pushed and has an acceleration of 1.5 m/s2. If the coefficient of kinetic friction is 0.20, what
is the force of the push?
3. A 5.0-kg object is resting on a surface with a coefficient of static friction of 0.80. What is the maximum force
that can be applied without moving the object?