Acceleration due to gravity / free fall.

Open Ended

Describe the motion of a pebble dropped from a tall bridge over water.

Open Ended

Two balls are released from the same height at the same time. The purple ball is falling straight down while the blue ball is rolling off the edge of the table. Which ball will hit the ground first? Explain your reasoning in terms of vertical and horizontal motion.

Draw

A ball is thrown straight into the air with an initial upward velocity of 19.62 m/s. Gravity applies an acceleration of -9.81 m/s2 to the ball. 4 seconds later, it hits the ground. Sketch the velocity versus time graph describing the object's motion over those 4 seconds below. [Reminder: this is velocity versus time, not displacement versus time.]

Open Ended

What do you think is causing this acceleration?

Multiple Choice

What impact does air resistance have on the velocity of a falling ball?

• It increases the velocity

• It decreases the velocity

• It has no impact

• It varies depending on the shape of the ball

Multiple Choice

A baseball is thrown up into the air. What happens to the velocity as the ball rises in the air?

• the velocity increases

• the velocity decreases

• the velocity remains constant

Multiple Choice

A ball is thrown upward with an initial speed of 30m/s. At what location will the ball be moving downward with a speed of 20m/s

• A

• B

• E

• F

Multiple Choice

A ball is thrown upwards and caught when it comes back down at the same height. In the absence of air resistance, the speed of the ball when caught would be

• less than the speed it had when thrown upwards.

• more than the speed it had when thrown upwards.

• the same as the speed it had when thrown upwards.

• need more information to determine.

Multiple Select

What equation(s) can you use to answer the question:

"How long does the ball stay in the air?

• $$x_f=x_0+v_0t+\frac{1}{2}at^2$$

• $$x_f=\ x_0\ +\ \frac{1}{2}\left(v_f+v_0\right)t$$

• $$v_f=v_0+at$$

• $$v_f^2=v_0^2+2a\left(x_f-x_0\right)$$

Multiple Choice

A ball is thrown straight up off a bridge with a velocity of 5 m/s. What is its velocity 2 seconds later?

• -5 m/s

• 0 m/s

• 5 m/s

• 10 m/s

Multiple Choice

On a mysterious orb in a distant galaxy, some alien creatures conduct an experiment to verify the value of "g" on their planet. They drop a rock from the ceiling 2.7 meters high and record the time it takes to hit the ground to be 0.61 seconds. Find the value of "g"

• 7.3 m/s/s

• 14.5 m/s/s

• 9.8 m/s/s

• 11.8 m/s/s

Poll

How confident do you feel about this topic now?

• Very confident
• Somewhat confident
• Not confident