More Projectile Motion Problems:

Unknown Angles and Velocities

  1. Wile E. Coyote tries his best to get that Road Runner by chasing him off a cliff. Despite his efforts the coyote of course falls. Unlike the cartoon (where Wile E drops straight down) he takes a parabolic path. If he runs with a speed of 4m/s before leaving the 30m high cliff, what is
  2. the time he is in the air? (2.47s)
  3. the distance from the cliff that he travels? (9.88m)
  4. his velocity right before hitting the ground (including an angle with respect to ground)? (24.5m/s, 80.6˚ below the horizontal)
  1. A golf ball is hit at an angle of 50° with respect to the ground and remains in the air for 6 seconds. Determine the initial velocity, the horizontal displacement, the peak height of the golf ball, and final velocity. (38.4 m/s, 148.2m, 44.1m, 38.4 m/s at 50° below the horizontal)
  1. A ball is tossed into the air at a speed of 64.0 m/s at an unknown angle. If the ball is observed to rise to a maximum height of 7.80 m, at what angle was the ball thrown relative to the ground? (11.1˚)
  1. A ball is launched from the ground into the air at an angle of 38.0 o (above the horizon) towards a vertical brick wall that is 15.0 m horizontally from the launch point. If the ball takes 1.30 seconds to collide with the wall,
  2. with what speed was the ball launched? (14.6m/s)
  3. did the ball hit the wall before or after reaching it’s maximum height?
  4. what is the height of the ball when it hits the wall? (3.4m)
  1. A student stands on the top of a building and throws his physics book downwards at an unknown angle at a speed of 46.0 m/s. The book is observed to hit the ground 15.0 m from the base of the building, take 0.42 seconds to hit the ground, and just barely miss his physics teacher. Neglecting any effects of air resistance,

a. / At what angle relative to the ground was the book thrown? (39.1˚ below the horizontal)
b. / How high is the building? (13m)
c. / At what speed and direction does the book hit the ground? (48.7m/s @ 42.8˚ below horizontal)
  1. Andre Agassi is practicing a few tennis strokes. A ball launcher at ground level launches a ball at 60m/s at an angle of 5˚. (Hint: the ball never reaches maximum height) If Andre stands 25m away from the launcher
  2. how long will the ball be in the air when it gets to him? (0.42s)
  3. what will the height of the ball be when it reaches him? (1.33m)
  4. what will the velocity (speed and direction) of the ball be when it reaches him? (59.8m/s at 1˚ above horizontal)

Ex: A rock is thrown at an angle of 15° above of the horizontal. The rock reaches a height of 12 m. a. What is the initial velocity of the rock? (59.1m/s)

b. How far does the rock travel horizontally before it hits the ground? (178.2m)