Relay Race 2 - Projectile Motion (2nd attempt)

A projectile is an object that moves in which directions?

• Horizontal only (X-direction)

• Vertical and Horizontal (y and x directions)

• x, y, and z directions (horizontal, vertical, and "into-the page")

• Vertical direction only (y-direction)

Suppose a 1.3 meter-tall woman throws a tennis ball with a velocity of 15 m/s. If she throws it at an angle of 60 degrees, then how far will it travel when it hits the ground? (Round your answer to the nearest meter)
Hint: How much time does it spend in the air?

• 21 m

• 13 m

• 10 m

• 20 m

The vertical motion of a projectile is considered...

• Dependent on the horizontal motion.

• Independent of the horizontal motion.

• the easiest part of the problem to solve.

• the same type of motion as the horizontal motion.

Here's a scenario: there is a passenger named Louisse on top of a stationary, double-decker bus. She throws a pebble from the back of the bus, and the pebble lands at the front. She repeats this action while the bus moves forward at a constant velocity. Where would the pebble land now?

• In front of the initial spot

• Behind the initial spot

• exactly where the passenger stands

• at the same spot it landed last time.

What is true about analyzing the motion of a projectile?

• We don't have to look at the vertical motion to see how it moves horizontally.

• The projectile's horizontal path depends on the strength of gravity.

• The method of joints must be used AFTER making a free body diagram of the structure.

• One must eat carrot cake before starting the analysis.

What will help you analyze the motion of a projectile? (Select all that apply)

• Recognize that the horizontal motion and vertical motion are independent of each other.

• Figure out how much time the object will spend in the air.

• Determine the time it takes for an object to reach its maximum height.

• The amount of time the objects spends moving vertically in the air, is the same amount of time that the objects moves horizontally in the air.

There is a person standing on the back of a pick-up truck with a tennis ball in-hand. The moment that they throw it forward with a certain velocity, the car moves in the opposite direction with the same velocity. What happens next?

• The ball will follow the path of a projectile, hitting the ground ahead of where it was thrown.

• The ball will follow the path of a projectile, hitting the ground behind where it was thrown.

• The ball will fall to the ground, landing at the same spot where it was thrown.

• The ball will stay in the air, indefinitely because the car moves backward at the same velocity as the ball's forward velocity, cancelling out all forces acting on the ball.

Examine the path of a projectile in the graph. Each dot represents a snapshot in time, 0.25 seconds apart. Which statement best describes what could be happening in this scenario?

• A basketball was thrown at the ground and bounced into the hoop.

• A football was thrown about 100 m.

• Someone tossed a set of keys over a fence, and it landed on the ground about 3 seconds later.

• Someone is jumping on a trampoline.

A heavy rock is dropped from rest at the top of a cliff and falls 88 m before hitting the ground. How long does the rock take to fall to the ground, and what is its velocity when it hits? (Round your answer to the nearest hundredth of a second)

• 8.24 s

• 8.22 s

• 4.23782 s

• 4.24 s

To get the video of cars flying through the air in movies, it is sometimes necessary to drive a car off a cliff and film it. Suppose a stunt man drives a car off a 15 meter-high cliff at a speed of 30 m/s.

How far does the car land from the base of the cliff?

(Ignore air resistance and any rotational motion)

• 25 m

• 30 m

• 35 m

• 40 m