Acceleration and Free Fall

In the final demonstration from 2.8, we put a piece of paper on top of a textbook and dropped the two objects together. If lighter objects fall at a slower rate than heavy objects, what should have happened to the paper?

• The paper should have separated from the book and landed at a later point in time.

• The paper should have stayed with the book the whole time during the fall.

Tags

NGSS.HS-PS2-1

In 2.8 our Free Fall Intro, we dropped various objects and measured how long it took them to hit the ground. What was the final take-home point from this activity?

• The weight of an object does not affect the rate at which it falls.

• Air resistance does not affect the rate at which an object falls.

• Heavier objects fall faster than lighter objects.

• Heavier objects have a greater acceleration than lighter objects.

Tags

NGSS.HS-PS2-1

What does free fall mean in physics?

• It means we only consider gravity acting on the object and we ignore air resistance.

• It means we consider all forces acting on a falling object, including air resistance and gravity.

• It means an object is falling with no acceleration.

• It means an object is falling with no forces acting on it.

Tags

NGSS.HS-PS2-1

During free fall, what kind of motion should all objects have?

• acceleration

• constant speed

• something else

Tags

NGSS.HS-PS2-1

In the final demonstration from 2.8, we put a piece of paper on top of a textbook and dropped the two objects together. What was the purpose of putting the paper on top?

• To get rid of air resistance acting on the paper

• To increase the weight of the paper

• To increase the air resistance acting on the book

• To decrease the weight of the book

Tags

NGSS.HS-PS2-1

Which ticker tape shows what a falling object should look like? Assume time goes from left to right for each tape.

• Tape 1

• Tape 2

• Tape 3

• Tape 4

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

How do you find velocity from a position vs time graph?

• The slope of a position vs time graph = velocity

• It is the corresponding y value from each x value

• It is the corresponding x value from each y value

• The slope of a velocity vs time graph = velocity

The slope of the red dotted line from t = 0 to t = 5 is equal to ________. This is the same as the __________________.

• 50/5 = 10 cm/s; average velocity

• 18/1 = 18 cm/s; instantaneous velocity

• 50 cm/s; acceleration

• 5 cm/s; displacement

The slope of the blue line from t = 3 to t = 4 seconds is ___________. This is the same as the _______________.

• 14/1 = 14 cm/s; instantaneous velocity

• 32/4 = 8 cm/s; average velocity

• 32 cm/s; acceleration

• 4 cm/s; displacement

Which lines represent average velocity on the graph to the right? (Remember average velocity is total displacement divided by total time.)

• The red dotted lines

• The horizontal axis

• The blue straight lines

• The vertical axis