APPC 9-26-24

Poll

Tuesday 9-24-24 Check In

How are you feeling today?

• Focused

• Annoyed/Mad

• Sleepy

• Hungry

1) Differentiate between all 3 of Newton's laws.
2) Match law to a given scenario.
3) Explain how N2L, a=Fnet/m, can be used to figure out acceleration of an elevator.

Objectives

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What happens to acceleration as force increases? Mass increases?

Multiple Choice

Which graph shows the mathematical relationship between Net Force (Fnet) and acceleration (a)?

Multiple Choice

Which graph shows the mathematical relationship between mass (m) and acceleration (a)?

Multiple Select

Which force is larger when elevator is moving UP?

• Fn

• Fg

• They're equal

Multiple Select

Which is the ΣFy equation for an elevator moving UP? Hint: Use direction of motion as POSITIVE

• ΣFy=Fn-Fg=ma

• ΣFy=Fg-Fn=ma

Multiple Select

Which force is larger when elevator is moving DOWN?

• Fn

• Fg

• They're equal

Multiple Select

Which is the ΣFy equation for an elevator moving DOWN? Hint: Use direction of motion as POSITIVE

• ΣFy=Fn-Fg=ma

• ΣFy=Fg-Fn=ma

Fill in the Blank

Two blocks are connected as shown in the diagram below. Assume that the ramp is frictionless. What is the acceleration of the block? (Please round to the nearest tenth)

.

/

^

Multiple Choice

If there is no friction, then the acceleration would be equal to

• mg

• sin(θ)mg

• g

• sin(θ)g

Multiple Choice

Which of the following is the best expression for the Normal Force?

• F_N = mg cos(ϴ)

• F_N = mg sin(ϴ)

• F_N = mg sin(180-ϴ)

• F_N = mg cos(90-ϴ)

Modified Atwood Machine- Extremely Common AP
Problem

Determine the acceleration of the blocks and the tension in the cord if m1 = 8 kg,
m2 = 12 kg, and the table surface is frictionless.

Draw

Draw an FBD for m1 and m2.

Draw

Write the ΣF for both m1 and m2

Use direction of motion as positive

Draw

Combine both force equations to solve for acceleration (a) of the system

Multiple Choice

According to N2L, what is formula to solve for a?

• $$a=\frac{Fnet}{m}$$

• $$a=\frac{m}{Fnet}$$

• $$a=Fnet\cdot m$$

Multiple Choice

Which of the following is the correct expression for acceleration of the system?

• $$a=m_2g$$

• $$a=\frac{m_2g}{m_1}$$

• $$a=\frac{m_2g}{m_1+m_2}$$

• $$a=\frac{m_2}{m_1+m_2}$$

Math Response

Plug the given info into your expression for a to solve

Type answer here

Correct Answer: a=\frac{120}{20}

Deg^°

Rad

Multiple Select

Based on the acceleration equation, which of the following would INCREASE acceleration in a modified Atwood setup?

Select ALL that applies

• Increase mass on the table (m1)

• Decrease mass on the table (m1)

• Increase hanging weight (m2)

• Decrease hanging weight (m2)

Multiple Select

If you were to add friction to the table, how would that affect the acceleration expression?

Select ALL that applies

• Numerator

• Denominator

• Increase acceleration

• Decrease acceleration