Question

Using a cable with a tension of 1370 N , a tow truck pulls a car 5.00 km along a horizontal roadway.

Part A

How much work does the cable do on the car if it pulls horizontally?

Part B

How much work does the cable do on the car if it pulls at 35.0? above the horizontal?

Part C

How much work does the cable do on the tow truck if it pulls horizontally?

Part D

How much work does the cable do on the tow truck if it pulls at 35.0? above the horizontal?

Part E

How much work does gravity do on the car in part A?

Answer 1

1.

Workdone is given by:

W = F.d = F*d*cos A

Workdone by cable on the car

F = +1370 N

A = 0 deg

d = 5 km = 5000 m

So,

W = 1370*5000*cos 0 deg

W = 6.85*10^6 J

Part B

A = 35 deg

So,

W = 1370*5000*cos 35 deg

W = 5.61*10^6 J

Part C

Since Force is in -ve x-axis and displacement is in +ve x-axis

A = 180 deg

So,

W = 1370*5000*cos 180 deg

W = -6.85*10^6 J

Part D

A = -35 deg = 145 deg

So,

W = 1370*5000*cos 145 deg

W = -5.61*10^6 J

Part E

gravity is downward, while displacement is eastward, So

A = 90 deg

Cos 90 deg = 0

W = F*d*cos 90 deg = 0 J

Please Upvote.