Conservation of Energy AP Physics

A ball is suspended by a lightweight string, as shown in the figure.   The ball is displaced to position 1 and released. The four labelled positions are evenly spaced along the arc of the ball's motion.  
Between which adjacent pairs is the gain in kinetic energy the greatest?

• 1 and 2

• 2 and 3

• 3 and 4

• They are all equal

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

A block of mass 3.0 Kg is suspended from a string, causing it to stretch 12cm before reaching equilibrium, as shown in the image.
The 3.0 Kg block is replaced with a 4.0 Kg block and it is released from the position shown above, at which the spring is unstretched.
How far will the 4.0 Kg block fall before the direction is reversed?

• 9 cm

• 18 cm

• 24 cm

• 32 cm

Tags

NGSS.MS-PS2-2

Use the law of conservation of energy (assume no friction) to find "E" for a 500-kg roller coaster following this path.

• 51.0 m/s

• 40.8 m/s

• 28.3 m/s

• 31.6 m/s

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Rank the scenarios from least to greatest kinetic energy right before they hit the ground

• 2<3<1<4

• 2<1<3=4

• 2<1<3<4

• 1=2=3=4

Tags

NGSS.MS-PS3-1

A roller coaster goes over a 10m high hill at 20m/s. What kind of energy does the roller coaster have?

• Potential

• Kinetic

• Both

• Neither

You 80kg and your date 65kg decide to go to the park. The two of you decide to see who can get the highest on the swings. At the bottom of your swing you are 1m above the ground and are traveling 5m/s. How high is your peak in the swing?

• 2.28m

• 1.28m

• 1m

• 9.8m

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

NGSS.MS-PS3-5

Energy is ....

• Weird

• Destroyed during explosions

• Conserved

• Created under the right circumstances

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

A crane lifts a steel beam weighing 8,000N, 300m in the air, then drops it onto a 20m high building below (for science!). The steel beam breaks through the ceiling. Assume that air resistance is negligible. Select the statement that best describes the scenario above.

• The beam has less energy when landing on the ground than it started with due to losing some to its surroundings

• The beam has the same amount of energy as it began with

• The kinetic energy as the beam touches the ground is equal to the potential energy it began with.

• The beam has a velocity of 19.8 m/s as it reaches the ground

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

NGSS.MS-PS3-5

How are work and energy related? 

• The work done by an external force acting on an object causes a change in the mechanical energy of the object.

• Work is the same thing as energy.  They are equal. 

• Energy is m*g*h, and work is 1/2*m*v²

Tags

NGSS.MS-PS3-5

A 5 kg object is lifted to a height of 10 meters. What is the potential energy of the object at this height?

• A) 50 J

• B) 100 J

• C) 500 J

• D) 1000 J