Collisions and Momentum Assessment

Summarize Newton’s Third Law of Motion in your own words.

Answer explanation

Newton's Third Law states that for every action, there is an equal and opposite reaction. This means that forces always occur in pairs; when one object exerts a force on another, the second object exerts a force of equal strength in the opposite direction.

Tags

NGSS.MS-PS2-1

What is momentum?

Answer explanation

Momentum is a physical quantity defined as the product of an object's mass and its velocity. It represents the motion of the object and is a vector quantity, having both magnitude and direction.

Tags

NGSS.HS-PS2-2

What factors determine how much momentum an object has?

Answer explanation

Momentum is determined by two factors: the mass of the object and its velocity. The formula for momentum is p = mv, where p is momentum, m is mass, and v is velocity. Thus, both mass and speed directly influence momentum.

Tags

NGSS.HS-PS2-2

A basketball is bounced against the ground. Describe the force exerted by the ball and/or ground when the ball collides with the ground.

Answer explanation

When the basketball collides with the ground, the ball exerts a downward force due to gravity, while the ground exerts an equal and opposite upward force on the ball, causing it to bounce back.

Tags

NGSS.HS-PS2-1

What do we mean when we say “momentum is conserved” during a collision?

Answer explanation

When we say 'momentum is conserved' during a collision, it means that the total momentum of the system before the collision equals the total momentum after the collision, assuming no external forces act on it.

Tags

NGSS.HS-PS2-2

Use Newton’s Third Law of Motion to describe the size and magnitude of forces exerted in a collision, such as that of a pool stick with a pool ball.

Answer explanation

According to Newton's Third Law, in a collision, the force exerted by the pool stick on the ball is equal in size and opposite in direction to the force exerted by the ball on the stick. Both forces are equal in magnitude.

Why is it harder to tackle a 100 kg football player running at a velocity of 2 m/s compared to a 75 kg football player running at 1.5 m/s? Explain your answer using concepts relating to momentum.

Answer explanation

Momentum is calculated as mass times velocity. The 100 kg player has a momentum of 200 kg·m/s (100 kg * 2 m/s), while the 75 kg player has 112.5 kg·m/s (75 kg * 1.5 m/s). The greater momentum of the first player makes him harder to tackle.

Tags

NGSS.HS-PS2-2

Is a car accident more dangerous when it involves one moving car and a stationary object or two moving cars? Explain.

Answer explanation

A car accident is more dangerous with two moving cars because the combined speed increases the force of impact, leading to greater potential for injury and damage compared to a moving car hitting a stationary object.

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

If two objects have the same mass, then the faster moving object has _____ momentum.

Answer explanation

Momentum is calculated as the product of mass and velocity. If two objects have the same mass, the one moving faster has more momentum. Therefore, the correct answer is that the faster moving object has more momentum.

Tags

NGSS.HS-PS2-2

The total momentum before a collision is _________ the total momentum after a collision.

• equal to 

• less than 

• more than

• It depends on the type of collision

Answer explanation

The total momentum before a collision is equal to the total momentum after a collision due to the law of conservation of momentum, which states that in a closed system, momentum is conserved.

Tags

NGSS.HS-PS2-2