Unit 3: Conservation Laws - Practice Game

What is the formula for calculating work done when a force is applied to move an object a certain distance in the direction of the force?

Answer explanation

The correct formula for calculating work done (W) when a force (F) moves an object a distance (d) in the direction of the force is W = F · d. This shows that work is the product of force and distance.

A 2 kg object is moving with a velocity of 3 m/s. Calculate its kinetic energy.

• 3 J

• 6 J

• 9 J

• 18 J

Answer explanation

Kinetic energy (KE) is calculated using the formula KE = 0.5 * m * v^2. For a 2 kg object moving at 3 m/s, KE = 0.5 * 2 * (3^2) = 0.5 * 2 * 9 = 9 J. Thus, the correct answer is 9 J.

Tags

NGSS.HS-PS3-1

Which of the following best describes gravitational potential energy?

• Energy stored in a compressed spring

• Energy due to an object's position above the ground

• Energy due to an object's motion

• Energy due to chemical reactions

Answer explanation

Gravitational potential energy is the energy an object possesses due to its height above the ground. The higher the object, the more gravitational potential energy it has, making 'Energy due to an object's position above the ground' the correct choice.

Tags

NGSS.MS-PS3-2

Using Hooke's Law, calculate the force exerted by a spring with a spring constant of 200 N/m when it is compressed by 0.1 m.

• 10 N

• 20 N

• 30 N

• 40 N

Answer explanation

Using Hooke's Law, F = kx, where k = 200 N/m and x = 0.1 m. Thus, F = 200 * 0.1 = 20 N. Therefore, the force exerted by the spring is 20 N.

• 49 J

• 98 J

• 490 J

• 980 J

Answer explanation

Gravitational potential energy (PE) is calculated using the formula PE = mgh. Here, m = 5 kg, g = 9.8 m/s², and h = 10 m. Thus, PE = 5 kg * 9.8 m/s² * 10 m = 490 J. Therefore, the correct answer is 490 J.

Tags

NGSS.HS-PS3-1

Which principle states that the total energy in a closed system remains constant?

• Conservation of Momentum

• Conservation of Energy

• Hooke's Law

• Newton's Third Law

Answer explanation

The principle of Conservation of Energy states that the total energy in a closed system remains constant, meaning energy can neither be created nor destroyed, only transformed. This makes it the correct choice.

Tags

NGSS.HS-PS3-4

A 3 kg object moving at 4 m/s collides elastically with a stationary 2 kg object. What is the velocity of the 3 kg object after the collision?

• 0 m/s

• 2 m/s

• 3 m/s

• 4 m/s

Answer explanation

In an elastic collision, both momentum and kinetic energy are conserved. After calculations, the final velocity of the 3 kg object is found to be 2 m/s, making this the correct answer.

Tags

NGSS.HS-PS2-2

What is the impulse experienced by an object when a force of 10 N is applied for 5 seconds?

• 10 Ns

• 20 Ns

• 50 Ns

• 100 Ns

Answer explanation

Impulse is calculated as force multiplied by time. Here, impulse = 10 N * 5 s = 50 Ns. Therefore, the correct answer is 50 Ns.

Tags

NGSS.HS-PS2-1

In an inelastic collision, which of the following is true?

• Kinetic energy is conserved

• Momentum is not conserved

• Objects stick together after collision

• Objects bounce off each other with no deformation

Answer explanation

In an inelastic collision, momentum is conserved, but kinetic energy is not. The correct choice is that objects stick together after the collision, which is a defining characteristic of inelastic collisions.

Tags

NGSS.HS-PS2-2

A spring with a spring constant of 150 N/m is stretched 0.2 m from its equilibrium position. Calculate the potential energy stored in the spring.

• 3 J

• 6 J

• 9 J

• 12 J

Answer explanation

The potential energy (PE) in a spring is calculated using the formula PE = 0.5 * k * x^2. Here, k = 150 N/m and x = 0.2 m. Thus, PE = 0.5 * 150 * (0.2)^2 = 3 J. Therefore, the correct answer is 3 J.

Tags

NGSS.HS-PS3-2