Question

31: A workman rolls a barrel of weight 2000 N up a plank of length 2.00 m and on to a lorry. The back of
the lorry is 0.80 m above the horizontal surface of the road. What is the work done on the barrel against
gravity?

a) 1000 J
b) 1600 J
c) 2500 J
d) 4000 J

Answer 1

http://imgur.com/kqjRqVA

Answer 2

Help please!

Answer 3

@Vincent-Lyon.Fr

Answer 4

@sarah_98

Answer 5

I haven't learned about this yet, but this might help: http://www.physicsclassroom.com/class/energy/Lesson-1/Calculating-the-Amount-of-Work-Done-by-Forces

Answer 6

Thanks , but still I don't get it .

Answer 7

@ShadowLegendX

Answer 8

the length of the ramp is actually not important, because all you're interested in is the work done AGAINST GRAVITY, which acts straight down. Since\[Work = Force*distance\]the box weighs 2000N, and is lifted a total of 0.8m, the work done against gravity is easy to find

Answer 9

Thank you very much . That was just what I needed !