Physics Work

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-PS3-5

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

NGSS.MS-PS3-5

The space shuttle (RIP) used to be transported to its launch pad by a large mobile platform. If the platform holds up the space shuttle 4.5x10⁶kg while rolling 800m to the launch pad, how much work does it do in holding up the shuttle?

• More than 0 but less than 1x10⁵ J

• More than 1x10⁵J but less than 1x10⁷J

• More than 1x10⁷ J but less than 1x10⁹ J

• More than 1x10⁹ J

• 0 J

Tags

NGSS.HS-PS3-1

What unit do we use for measuring power?

• Watts 

• Joules 

• Newtons 

• ft/lbs

Energy is ....

• Weird

• Destroyed during explosions

• Conserved

• Created under the right circumstances

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Which is the equation for work?

• W = Fd

• W = Fa

• W = ma

• W = md

Tags

NGSS.MS-PS3-5

The product of the component of a force along the direction of a displacement and the magnitude of the displacement is called ....

• weight

• work

• gravity

• net force

The unit for work is ​ (a)  

• J

• kg

• m/s

• N

A person pulled a sled with a constant net horizontal force of 6 N and caused the sled to move through the field. How much work was done on the sled if it moved a distance of 2 km?

• 3 J

• 12 J

• 8 J

• 1.2 J

One of the Huskies basketball players lifted a set of weights a vertical distance of 2.0 m. If a constant net force of 250 N is exerted on the weights, what is the net work done on the weights? Use correct sig figs

• 500 J

• 5.0 x 10^2 N

• 5.0 x 10^2 J

• 5.0 x 10^3 J

Tags

NGSS.HS-PS3-1