Test 2 Study Guide
Free Fall, Vectors, Projectile Motion
Free Fall/4 Kinematic Equations
Pg 69 # 19, 21, 23, 25, 26, 28, 31, 32, 34, 38-40
Vector Addition
Pg 108 # 1-3, 6a, 8, 11-21, 24-26
Add the following vectors.
- 3.0 m/s, 45 deg and 5.0 m/s, 135 deg
- 5.0 m/s, 45 deg and 2.0 m/s, 180 deg
- 4.0 m/s, 135 deg and 4.0 m/s, 315 deg
- 2.0 m/s, 150 deg and 4.0 m/s, 225 deg
- 3.0 m/s, 45 deg and 5.0 m/s, 135 deg and 2.0 m/s, 60 deg
- 4.0 m/s, 90 deg and 2.0 m/s, 0 deg and 2.0 m/s, 210 deg
- 6.0 m/s, 135 deg and 7.0 m/s, 20 deg and 3.0 m/s, 290 deg
- 2.0 m/s, 35 deg and 7.0 m/s 160 deg and 4.0 m/s, 210 deg
Projectile Motion
Pg 109 # 27-35, 37
Horizontal Launch
1)A rocket is accelerating vertically upward at 30 m/s2 near Earth's surface. A bolt separates from the rocket. What is the acceleration of the bolt?
2)A projectile leaves a gun at the same instant that the target is dropped from rest. If the projectile is initially aimed straight at the target, will it hit the target?
3)What is the relationship between the maximum height of the projectile, the projectile's range, and the launch angle?
4)A ball is thrown from a bridge horizontally at a speed of 8m/s. Just before it hits the ground it is moving 50m/s vertically. How long was the ball in the air? How tall was the bridge? What was the range of the throw?
5)A ball is thrown from a bridge horizontally. It spends 8s in air and has a range of 50m. How tall was the bridge? How fast was the ball traveling vertically just before it hit? How fast was the ball traveling horizontally just before it hit?
6)A ball is thrown from a 75m tall bridge and travels 150m away. How long did it stay in the air? How fast was it traveling both vertically and horizontally just before it hit the ground?
7)A girl runs straight off a cliff with a horizontal velocity of 2.64 m/s and falls for 1.48s before landing on the ground. What is the horizontal component of her velocity (in m/s) just before she reaches the ground? How far from the cliff (in m) does the girl hit the ground?
8)A car drives straight off the edge of a cliff that is 54 m high. The police at the scene of the accident note that the point of impact is 130 m from the base of the cliff. How fast was the car traveling when it went over the cliff?
Angled Release
Problem 1: A projectile is fired with an initial velocity of 120 m/s at an angle above the horizontal. If the projectile's initial horizontal speed is 55 m/s, then at what angle was it fired?
Problem 2: A rock is thrown with an initial vertical velocity component of 30 m/s and an initial horizontal velocity component of 40 m/s.
a. What will these velocity components be one second after the rock reaches the top of its path?
b. Assuming the launch and landing heights are the same, how long will the rock be in the air?
c. Assuming the launch and landing heights are the same, how far will the rock land from where it was thrown?
Problem 2 Solution
Problem 3: Two tennis ball launchers shoot balls at the same time, angle and initial speed from different floors of a tall building. The balls land in the street below. Ignore air resistance.
a. Which ball will have the greater acceleration while in flight? Explain your reasoning.
b. Which ball will hit farther from the base of the building? Explain your reasoning.
c. Which ball will reach a greater maximum height? Explain your reasoning.
d. Which ball will be going faster just before hitting the street? Explain your reasoning.
e. How could you adjust only the angle of the upper launcher so that the ball hits in the same place as the ball from the lower launcher? Explain your reasoning.
f. How could you adjust only the angle of the lower launcher so that the ball hits in the same place as the ball from the upper launcher? Explain your reasoning.
Problem 3 Solution
Problem 4: Balls A and B are launched from different heights. The reach the same maximum height at exactly the same point in space.
a. Which ball has a greater initial vertical component of velocity? Explain.
b. Which ball has a greater initial horizontal component of velocity? Explain.
c. Which ball has the larger launch angle? Explain.
d. Which ball has greater acceleration while in flight? Explain.
e. Which ball will land farther from the launchers? Explain.
f. Which ball takes longer to reach maximum height? Explain.
g. If the balls were launched simultaneously, would they collide before landing? Explain.
Problem 4 Solution
Problem 5: If a person can jump a horizontal distance of 3 m on Earth, how far could the person jump on the moon where the acceleration due to gravity is one-sixth of that on earth (1.7 m/s/s)?
Problem 6: A brick is thrown upward from the top of a building at an angle of 25 degrees above the horizontal and with an initial speed of 15 m/s. If the brick is in the air for 3 seconds, how high is the building? (Draw a picture.)
Problem 6 Solution
Problem 7: A daredevil tries to jump a canyon of width 10 m. To do so, he drives his motorcycle up an incline sloped at an angle of 15 degrees. What minimum speed is necessary to clear the canyon?