Gravity and Motion Review!
1. What is Terminal Velocity? The motion of a body when only the force of gravity is acting on the body. The curved path of a thrown object near Earth’s surface. The constant velocity of a falling object when the force of gravity is balanced by air resistance. The force that opposes the motion of objects thrown in the air. 1. What is Terminal Velocity?
C. The constant velocity of a falling object when the force of gravity is balanced by air resistance. ANSWER
The force that opposes the motion of objects thrown in the air. The curved path of a thrown object near Earth’s surface. A song by Tom Petty and the Heartbreakers The motion of a body when only the force of gravity is acting on the body. 2. What is Free Fall?
d. The motion of a body when only the force of gravity is acting on the body. ANSWER
3. What is Projectile Motion? The motion of a body when only the force of gravity is acting on the body. The curved path of a thrown object near Earth’s surface. The constant velocity of a falling object when the force of gravity is balanced by air resistance. The force that opposes the motion of objects thrown in the air. 3. What is Projectile Motion?
b. The curved path of a thrown object near Earth’s surface. ANSWER
The force that opposes the motion of objects thrown in the air. The curved path of a thrown object near Earth’s surface. A song by Tom Petty and the Heartbreakers The motion of a body when only the force of gravity is acting on the body. 4. What is Air Resistance?
a. The force that opposes the motion of objects thrown in the air. ANSWER
5. Which of the following is in projectile motion? A feather falling in a vacuum A cat leaping on a toy A car driving up a hill A book laying on a desk 5. Which of the following is in projectile motion?
b. A cat leaping on a toy. ANSWER
6. How is the acceleration of falling objects affected by gravity? Gravity is not the same for all falling objects. Gravity prefers pulling larger objects over smaller objects. Gravity is constant for all falling objects. Gravity prefers pulling smaller objects over larger objects. 6. How is the acceleration of falling objects affected by gravity?
c. Gravity is constant for all falling objects. ANSWER
The cannonball lands first. The baseball lands first. The ball lands at the same time. The ball with the larger volume lands first. 7. If a baseball and a cannonball are dropped from the same height at the same time, and there is no air resistance, which ball will hit the ground first?
c. The balls land at the same time. ANSWER
29.4 m/s 36.2 m/s 18.6 m/s 15 m/s 8. A boy standing on a high cliff dives into the ocean below and strikes the water after 3 seconds. What is the boy’s velocity when he hits the water? (Hint gravity pulls all objects at a rate of 9.8 meters/second)
a. 29.4 m/s – 9.8 x 3 = 29.4 m/s ANSWER
9. What feature of an object does not affect air resistance? Its size Its chemical properties Its shape Its speed 9. What feature of an object does not affect air resistance?
b. Its chemical properties ANSWER
10. When does an object reach its terminal velocity? When the upward force of air resistance equals the downward force of gravity. When the downward force of gravity is greater than the upward force of air resistance. When the downward force of air resistance is equal to the upward force of gravity. When the upward force of air resistance is greater than the downward force of gravity. 10. When does an object reach its terminal velocity?
a. When the upward force of air resistance equals the downward force of gravity. ANSWER
13.3 m/s 6.3 m/s 34.3 m/s 2.8 m/s 11. A rock at rest falls off a tall cliff and hits the valley below after 3.5 seconds. What is the rock’s velocity as it hits the ground? (Hint: what is the rate of constant acceleration?)
c. 34.3 m/s ANSWER
12. Why do astronauts appear to be floating when they are in space? They are actually in free fall with the shuttle around Earth. It’s really good special effects. They weigh more in space. They are forced to eat bad food. 12. Why do astronauts appear to be floating when they are in space?
a. They are actually in free fall with the shuttle around the Earth. ANSWER
GOOD LUCK TOMORROW!! STUDY HARD!!