Conservation of Energy HW

A system that initially has 100 J of total mechanical energy experiences a friction force that does -30 J of work on the system. What is the resulting total mechanical energy of the system?

• 130 J

• 100 J

• 70 J

• -30 J

Tags

NGSS.MS-PS3-5

NGSS.MS-PS2-2

A penguin slides down an icy slope with negligible air resistance. If the penguin’s potential energy decreases by 40 J, by how much does the penguin’s kinetic energy change?

• It increases by 40 J

• It decreases by 40 J

• It stays the same

• It increases by 20 J

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

NGSS.MS-PS3-5

A raindrop falling from the sky has 100 J of gravitational potential energy and 50 J of kinetic energy. At a later point in time, the raindrop has 25 J of gravitational potential energy and 75 J of kinetic energy. Is total mechanical energy conserved as the raindrop falls?

• Yes, it remains constant

• No, it decreases

• No, it increases

• Cannot be determined

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-5

NGSS.MS-PS3-4

A ball is rolled up a slope (without slipping). Choose the combination that correctly describes how each quantity changes as the ball rolls up: Kinetic Energy (Increases, Decreases, Stays the Same); Potential Energy (Increases, Decreases, Stays the Same); Total Mechanical Energy (Increases, Decreases, Stays the Same).

• Kinetic increases; Potential decreases; Total stays the same

• Kinetic decreases; Potential increases; Total increases

• Kinetic stays the same; Potential increases; Total increases

• Kinetic decreases; Potential increases; Total stays the same

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-5

NGSS.MS-PS3-4

A shopping cart is rolling on a flat surface when it hits some groceries and comes to a stop. Choose the combination that correctly describes how each quantity changes: Kinetic Energy (Increases, Decreases, Stays the Same); Potential Energy (Increases, Decreases, Stays the Same); Total Mechanical Energy (Increases, Decreases, Stays the Same).

• Kinetic decreases; Potential stays the same; Total decreases

• Kinetic decreases; Potential increases; Total stays the same

• Kinetic increases; Potential stays the same; Total increases

• Kinetic stays the same; Potential stays the same; Total stays the same

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

A woman pushes a crate up a hill with constant speed. Choose the combination that correctly describes how each quantity changes: Kinetic Energy (Increases, Decreases, Stays the Same); Potential Energy (Increases, Decreases, Stays the Same); Total Mechanical Energy (Increases, Decreases, Stays the Same).

• Kinetic stays the same; Potential increases; Total increases

• Kinetic increases; Potential increases; Total stays the same

• Kinetic decreases; Potential decreases; Total decreases

• Kinetic stays the same; Potential stays the same; Total stays the same

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

NGSS.MS-PS2-2

A professor drops a ball from the top of a building and the ball falls toward the ground. Choose the combination that correctly describes how each quantity changes: Kinetic Energy (Increases, Decreases, Stays the Same); Potential Energy (Increases, Decreases, Stays the Same); Total Mechanical Energy (Increases, Decreases, Stays the Same).

• Kinetic increases; Potential decreases; Total stays the same

• Kinetic increases; Potential increases; Total increases

• Kinetic decreases; Potential increases; Total decreases

• Kinetic stays the same; Potential stays the same; Total stays the same

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

NGSS.MS-PS3-5

A 55-kg seal is at rest on top of a slick ramp that is 1.5 m high. The seal starts to slide down the ramp. How fast, in m/s, will it be going at the bottom of the ramp? Use 9.8 m/s^2 for acceleration due to gravity. Round your answer to 1 decimal place.

(a)  

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

NGSS.MS-PS2-2

NGSS.MS-PS2-4

An archer shoots an arrow that has a mass of 0.4 kg directly up in the air to a height of 120 m. What was the initial speed, in m/s, of the arrow when it was first shot out? Use 9.8 m/s^2 for the acceleration due to gravity. Round your answer to 1 decimal place.

(a)  

Tags

NGSS.MS-PS3-1

NGSS.MS-PS2-2

A cart that has 16 joules of kinetic energy travels on a frictionless, horizontal surface toward a horizontal spring. If the cart comes to rest after compressing the spring a distance of 1.0 m, what is the spring constant of the spring in N/m?

(a)  

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2