Work-energy theorem

45 J of work were done on the object that moved 5 meters. How much force was applied to the object?

• 8 N

• 225 N

• 9 N

• 0 N

Tags

NGSS.HS-PS2-1

The net work done by a net force acting on an object is equal to the change in the kinetic energy of the object.

• Force-Work Theorem
• Work-Kinetic Energy Theorem
• Force-Kinetic Energy Theorem
• Work-Force Theorem

Tags

NGSS.HS-PS3-1

A 10.0 kg box is accelerated from 2.0 m/s to 4.0 m/s. What is the amount of work needed to accelerate the box?

• 50 J

• 60 J

• 20 J

• 45 J

Tags

NGSS.HS-PS3-1

When my velocity triples, my kinetic energy increases by ______ times.

• 9
•  3 
• 1.5
• 4.5

Tags

NGSS.MS-PS3-1

Calculate the force necessary to move a 1000 kg car from rest to 25 m/s in 130 m.

• 19 N

• 25,0000 N

• 2400 N

• 3.3 x 10⁶ N

Tags

NGSS.HS-PS2-1

What are the units for Work?

• Newtons

• Kilograms

• Joules

• Moles

What is the equation for Kinetic Energy (KE)?

• $KE\ =\ 2mv^2$

• $KE\ =\ 2mv$

• $KE\ =\ mv^2$

• 
  

  $KE\ =\ \frac{1}{2}mv^2$

Tags

NGSS.HS-PS3-2

Work can also be shown as

 $W\ =\ \Delta KE$ 

How do you find  $\Delta KE$  ?

•  $KE_i\ -\ KE_f$  

•  $KE_f\ -\ KE_i$  

•  $KE\ +\ KPOP\ =\ BbyMtl$  

•  $42?$  

Tags

NGSS.HS-PS3-1

A 80.0-kg fireman slides down a 3.00-m pole by applying a frictional force of 400. N against the pole with his hands. If he slides from rest, how fast is he moving once he reaches the ground?

• 2.1 m/s

• 4.2 m/s

• 5.5 m/s

• 8.0 m/s

Tags

NGSS.HS-PS2-1

For an object sliding on the ground, the friction force

• always acts in the same direction as the displacement

• always acts in a direction perpendicular to the displacement

• always acts in a direction opposite to the displacement.

• acts either in the same direction as the displacement or in the

  direction opposite to the displacement depending on the value of the coefficient of kinetic friction.

Tags

NGSS.HS-PS2-1