Energy - Ch. 5

Can you feel the Kenergy?

100

The equation for kinetic energy.

What is K=1/2mv²?

200

The only factor that determines the final speed of an object that falls from rest. 

What is the height from which an object falls?

300

The kinetic energy of a 1.0 kg object that travels at 2.0m/s.

What is 2 J?

400

The velocity of a 6 kg object that is accelerated by a spring with a spring constant of 10 N/m over a distance of 2 m.

What is 2.58 m/s?

500

The expression for the velocity of an object with only gravitational potential initially and kinetic energy finally. 

Hint: There is no dependence on mass. 

What is v=sqrt(2gh)?

Nonconservative but not necessarily liberal forces

100

An expression for the work done by a nonconservative force.

What is W_nc=E_f-E_i?

200

A nonconservative force characterized by the molecular interactions between two surfaces.

What is friction?

300

The work done by a nonconservative force on a system that begins with 10 J and ends with 9 J. 

What is 1 J?

400

The work done by air resistance on a 3 kg object that has an initial height of 5 m and falls, accelerating to a final velocity of 9 m/s. 

What is 28.5 J? 

500

The expression for the work done by a nonconservative force on an object that is accelerated by a spring to some velocity. 

W_nc=1/2(kx²-mv²)

Watt do you mean?

100

The equation for power. 

What is P=W/t?

200

The unit for power.

Watt is a Watt?

300

The power of a system that does 55 J of work in 10 s. 

What is 5.5 W?

400

The power needed in a pulley system to pull a 6 kg block along a 2 m path with a 100 N force over 5 seconds. 

What is 40 W?

500

The expression for power in terms of force and velocity.

What is P=F*v?

Potentially

100

The corresponding equations for gravitational potential energy and spring potential energy.

What are PE_g=mgh and PE_s=1/2kx²?

200

This happens when you change your reference point for potential energy.

What is nothing?

300

The potential energy of an object with mass 5 kg at a height 7 m off the ground, which is the reference level.

What is 350 J?

400

The height to which a spring system with spring constant 10 N/m and compressed by 150 cm can push a 5 kg object, provided the spring launches the object up.

What is 0.225 m?

500

The expression for the maximum height of an object pushed straight up by a spring system.

h=0.5kx²/mg

Work It

100

The equation for work.

What is W=Fcos(theta)x

200

The method by which an objects kinetic energy changes. 

What is work?

300

The work done by a 10 N force over a distance of 35 m.

What is 350 J?

400

The magnitude of the work done by gravity on a 7 kg object as it falls down 10 m. 

What is 700 J?

500

The expression for the angle between the work done on an object and the displacement of the object. 

theta=cos^-1(W/Fd)