Exit Check 2.1 - 1st Law

2.1.1

Match the following terms with a good description of them

• Hypothesis

• A description of what effect will happen because of a given cause

• Law

• An explanation of why observed patterns happen

• Observation

• A fact or measurement

• Theory

• A predicted answer to an experiment question

Answer explanation

Use your vocabulary and notes to help.

Observations are factual and do not include explanations.

A hypothesis is a testable prediction that answers a question.

A theory explains why something happens and is supported by evidence.

A law describes what will happen under certain conditions and is based on repeated observations.

2.1.1

Match the following ideas with an example of each:

• Hypothesis

• In an experiment a toy car with less mass will go faster than a toy car with more mass.

• Theory

• The toy car traveled 10 meters.

• Law

• Gravity pulls objects together because all objects are made of mass, and all mass attracts other mass.

• Observation

• An object will not accelerate unless it is acted upon by an outside net force.

Answer explanation

Use your vocabulary and notes to help.

Observations are factual and do not include explanations.

A hypothesis is a testable prediction that answers a question.

A theory explains why something happens and is supported by evidence.

A law describes what will happen under certain conditions and is based on repeated observations.

Tags

NGSS.HS-PS1-2

NGSS.HS-LS1-3

2.1.2

Is there an outside force acting to create the motion you see in the animation?

• The object's speed does not change, so there is no force

• The direction the object moves is changing, there must be an outside force.

• The center of the object doesn't move, so there is no outside force.

• The object is above the ground, there is a downward force.

Answer explanation

To answer these questions, use two key ideas.

First, acceleration means any change in motion such as speeding up, slowing down, or changing direction.

Second, according to Newton’s First Law, an object’s motion won’t change unless there’s an outside net force. So if you see acceleration, a net force is acting. If there’s no acceleration, there’s no net force.

Tags

NGSS.HS-PS2-1

2.1.2

Which statement best summarizes the scientific concept shown in the cartoon?

• A falling body accelerates at a constant speed.

• The motion of an object is constantly changing due to magnetic forces.

• The force of friction causes an object in motion to move faster.

• A body in motion will remain in motion unless influenced by an outside force.

Answer explanation

To answer these questions, use two key ideas.

First, acceleration means any change in motion such as speeding up, slowing down, or changing direction.

Second, according to Newton’s First Law, an object’s motion won’t change unless there’s an outside net force. So if you see acceleration, a net force is acting. If there’s no acceleration, there’s no net force.

Tags

NGSS.HS-PS2-1

2.1.2

What best describes the net force acting on the barbell while the weightlifter holds it steady (at rest) above his head?

• The object is not in motion, so there is no net force.

• It is heavy, so the net force is pointing down.

• It is heavy but he is strong, so the net force is pointing up.

• There are no forces acting on the barbell.

Answer explanation

To answer these questions, use two key ideas.

First, acceleration means any change in motion such as speeding up, slowing down, or changing direction.

Second, according to Newton’s First Law, an object’s motion won’t change unless there’s an outside net force. So if you see acceleration, a net force is acting. If there’s no acceleration, there’s no net force.

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

2.1.1

Why is it important that scientists modify scientific theories when important new information is discovered?

• to confuse other scientists

• to keep the theory interesting and fresh

• to keep the theory as accurate and effective as possible

• to make sure the general public does not understand the theory

Answer explanation

Use your vocabulary and notes to help.

Observations are factual and do not include explanations.

A hypothesis is a testable prediction that answers a question.

A theory explains why something happens and is supported by evidence.

A law describes what will happen under certain conditions and is based on repeated observations.

Tags

NGSS.HS-PS1-2

2.1.1

How does the use of the word theory in science compare to how it is used in everyday speech?

• people normally think a theory is just an idea but in science a theory has been tested many times and proven correct many times.

• People normally think a theory has been tested and proven but in science it is just an idea.

• There is no difference, a theory always means "just an idea"

• A Theory is a reason to make a youtube channel, it doesn't really happen in science.

Answer explanation

Use your vocabulary and notes to help.

Observations are factual and do not include explanations.

A hypothesis is a testable prediction that answers a question.

A theory explains why something happens and is supported by evidence.

A law describes what will happen under certain conditions and is based on repeated observations.

2.1.2

A race car is going around a corner on its race track.

The car ​ (a)   accelerating because it ​ (b)   ​changing direction. By the 1st Law, this means the net force ​ (c)   zero.

• is
• isn't

Answer explanation

To answer these questions, use two key ideas.

First, acceleration means any change in motion such as speeding up, slowing down, or changing direction.

Second, according to Newton’s First Law, an object’s motion won’t change unless there’s an outside net force. So if you see acceleration, a net force is acting. If there’s no acceleration, there’s no net force.

Tags

NGSS.HS-PS2-1

2.1.2

A student is running at 5 m/s in a straight line.The student ​ (a)   accelerating because their velocity ​ (b)   changing. By the 1st Law, this means the net force ​ (c)   zero.

• is
• isn't

Answer explanation

To answer these questions, use two key ideas.

First, acceleration means any change in motion such as speeding up, slowing down, or changing direction.

Second, according to Newton’s First Law, an object’s motion won’t change unless there’s an outside net force. So if you see acceleration, a net force is acting. If there’s no acceleration, there’s no net force.

Tags

NGSS.HS-PS2-1

2.1.2

A stone's weight pushes down on the earth but neither the stone nor the earth moves. The objects ​ (a)   accelerate because they ​ (b)   start moving. By the 1st Law, this means there ​ (c)   be a balancing force to keep the net force zero.

• does
• don't
• mustn't
• must

Answer explanation

To answer these questions, use two key ideas.

First, acceleration means any change in motion such as speeding up, slowing down, or changing direction.

Second, according to Newton’s First Law, an object’s motion won’t change unless there’s an outside net force. So if you see acceleration, a net force is acting. If there’s no acceleration, there’s no net force.

Tags

NGSS.HS-PS2-1