Work Done by Force-Tesla

Work Done by Force-Tesla

​Some text here about the topic of discussion.

WORK

• quantity that exists whenever a force acting upon an object causes a displacement.

• scalar quantity

Two Important Conditions in the Definition of Work

• The force must move the object.

• The force must have a component parallel to the direction of motion.

Situational Analysis

Multiple Choice

Which of the following situations shows that work is done?

• teacher sitting on a chair

• book resting on a table

• key chain hanging from a bag

• a ball being rolled on the floor

Multiple Choice

In which of the following situations is work NOT done?

• pushing a cart in a store

• shooting a basketball

• holding a 20 pound box above the floor

• running a mile

Multiple Choice

In which of this cases is work being done?

• a student sleeping

• a student pushing a locked door

• a student carrying his chair into another room

• a student sitting on the carpet

Multiple Choice

True or False: You do work when you mannequin pose with an object in your hand.

• True

• False

Video Response

How can you describe the work done by a constant force?

Open Video Recorder

Work done

​When the angle between force and surface is zero degrees the work done simply calculated by

W=Fs

W is work done by a constant force (J), F is force (N) and s is displacement (m).​

example :

A force of 800 N moves an object over a distance of 18 metres. Calculate the work done.

solution:

F= 800 N, s = 18 m; W=....?

W=F*s=800*18=14400 J​

​

Fill in the Blanks

A force of 600 N moves an object over a distance of 18 metres. Calculate the work done.

Fill in the Blanks

1400 J of work is done moving an object over a distance of 70 metres. What force was used to move the object?

Fill in the Blanks

3500 J of work is done moving an object over a distance of 35 metres. What force was used to move the object?

Fill in the Blanks

1.95 kJ of work is done moving an object over a distance of 150 metres. What force was used to move the object?

Fill in the Blanks

10.8 kJ of work is done moving an object over a distance of 0.018 km. What force was used to move the object?

Work done

​When the angle between force and surface not zero degrees the work done simply calculated by

W=Fs cosθ

W is work done by a constant force (J), F is force (N) and s is displacement (m), θis angle between force and the surface. ​

example :

A force of 800 N moves an object over a distance of 18 metres on a horizontal surface. If the angle between force and the surface is 60⁰. Calculate the work done.

solution:

F= 800 N, s = 18 m; W=....?

W=F*s cosθ=800*18 cos60⁰=14400*1/2=7200J​

​

Open Ended

A force of 400 N moves an object over a distance of 8 metres on a horizontal surface. If the angle between force and the surface is 60⁰. Calculate the work done.

Multiple Choice

If Jay Loppy pushes his van 20 meters, with a force of 100N; at an angle of 60^o;how much work is done?

• 2,000J

• 40,000J

• 1000J

• 800,000J

Multiple Choice

Sandi pushes his car 20 meters, with a force of 1000N; at an angle of 60^o;how much work is done?

• 2,000J

• 20,000J

• 1000J

• 800,000J

Open Ended

Arrange the work done by force from the lowest to the highest!

A. The force of 20 N moves the object 20 m away.

B. Sandi push the car with 2000 N force and it moves 1 m away.

C. Darel push the object with 200 N force and it moves 1 m away.

D. A 50 N force 60^₀ to horizontal surface moves an object 600 m away.

E. A 500 N force 60^₀ to horizontal surface moves an object 600 m away.