Review 2

What is the formula for calculating velocity?

• Distance × Time

• Distance / Time

• Distance + Time

• Distance – Time

Answer explanation

Velocity is calculated using the formula Distance / Time. This means that to find the velocity, you divide the total distance traveled by the time taken to travel that distance.

If a car travels 100 meters in 5 seconds, what is its velocity?

• 15 m/s

• 20 m/s

• 25 m/s

• 30 m/s

Answer explanation

To find velocity, use the formula: velocity = distance/time. Here, distance = 100 meters and time = 5 seconds. Thus, velocity = 100 m / 5 s = 20 m/s, which is the correct answer.

What is acceleration?

• The change in velocity over time

• The change in distance over time

• The force applied over time

• The distance traveled in a straight line

Answer explanation

Acceleration is defined as the change in velocity over time. It measures how quickly an object's speed or direction changes, making it the correct choice among the options provided.

Tags

NGSS.HS-PS2-1

What is the formula for calculating acceleration?

• Final velocity – Initial velocity

• Final velocity + Initial velocity

• (Final velocity – Initial velocity) / Time

• Final velocity × Initial velocity

Answer explanation

Acceleration is calculated using the formula (Final velocity – Initial velocity) / Time. This shows how much the velocity changes over a specific time period, making it the correct choice.

Tags

NGSS.HS-PS2-1

Which of the following is a contact force?

• Gravity

• Magnetic force

• Friction

• Electrostatic force

Answer explanation

Friction is a contact force because it arises from the interaction between surfaces in contact. In contrast, gravity, magnetic force, and electrostatic force act at a distance without direct contact.

Balanced forces result in:

• An object moving faster

• An object staying at rest or moving at constant speed

• An object accelerating

• An object changing direction

Answer explanation

Balanced forces mean that the total force acting on an object is zero, resulting in no change in motion. Therefore, an object will either stay at rest or continue moving at a constant speed.

Tags

NGSS.HS-PS2-1

Unbalanced forces result in:

• No movement

• A change in motion

• Constant velocity

• Equal forces acting in opposite directions

Answer explanation

Unbalanced forces cause a change in motion, as they result in acceleration or deceleration. This contrasts with balanced forces, which maintain constant velocity or no movement.

Tags

NGSS.HS-PS2-1

Which force pulls objects toward each other?

• Friction

• Gravity

• Applied force

• Tension

Answer explanation

Gravity is the force that pulls objects toward each other, such as the Earth pulling us down. It acts on all masses, making it the correct answer to the question.

Tags

NGSS.HS-PS2-4

Which force opposes motion between two surfaces?

• Magnetic force

• Electrostatic force

• Friction

• Tension

Answer explanation

Friction is the force that opposes motion between two surfaces in contact. It acts to resist the sliding or rolling of one surface over another, making it the correct answer to the question.

Which of the following is an example of a non-contact force?

• Friction

• Air resistance

• Gravity

• Tension

Answer explanation

Gravity is a non-contact force that acts at a distance, pulling objects toward each other without physical contact. In contrast, friction, air resistance, and tension require contact between surfaces or objects.

Tags

NGSS.HS-PS2-4