# Physics

posted by .

A 855 N crate rests on the floor.

a) How much work is required to move it at constant speed 7.7 m along the floor against a friction force of 180 N?

b) How much work is required to move it at constant speed 7.7 m vertically?

I really NEED help I am very lost with physics!!!!

• Physics -

a) work= force applied*distance
and force applied has to equal friction.
b) work=increase in gravitational PE
= mass*g*height

Very Lost? There is no reason for that. Go to your nearest college bookstore, or Barnes Noble, and examine the Schaum's Outline Series, xxxx Physics. There are several in that series, I like the Physics for engineers and scientists, but frankly, it is heavy in calculus...most like the college physics issue. They are filled with worked example problems, with explainations. They are priced very reasonable.

• Physics -

I figured A out it was 1386 J, but I can not figure out B I used 855X9.8x7.7 and that's not right can you tell me where I went wrong?

• Physics -

well, there is no answer for b, unless you know the height. As height changes, gravitational potenial energy changes, so you had to put more energy in. IF this is all there is to the problem, you cannot do it, the problem is deficient. 7.7 is the speed. you cannot get height frm speed without time...however, you can get the POWER in watts used (Power=work/time)
Power= m*g*speed
and
work= Power*time but you have to have again height to get the time.

• Physics -

7.7 is the height in this problem not the speed.

## Similar Questions

1. ### Physics

Sally applies a horizontal force of 500 N with a rope to dtag a wooden crate across a floor with a constant speed. The rope tied to the crate is pulled at an angle of 67.5 degrees. a) How much force is exerted by the rope on the crate?
2. ### Physics- Work

A worker pushes a 1.50*10^3 N crate with a horizontal force of 345 N a distance of 24.0 m. Assume the coefficient of kinetic friction between the crate and the floor is 0.220. a. How much work is done by the worker on the crate?
3. ### physics

a 650 newton crate rests on the floor. how much work is required to move it at a constant speed, 3 meters against a friction force of 150 Newtons
4. ### Physics

Question # 1 Marks = 12 A worker pushes 25Kg crate a distance of 5m along a level floor at constant velocity by pushing horizontally on it. The coefficient of kinetic frication between the crate and the floor is 0.23. (a) What magnitude …
5. ### Physics

A worker pushes 25Kg crate a distance of 5m along a level floor at constant velocity by pushing horizontally on it. The coefficient of kinetic frication between the crate and the floor is 0.23. (a) What magnitude of force must the …
6. ### physics

a 840 N crate rests on the floor how much work is required to move it at constant speed 5.5m along the floor against a friction force 180 N?
7. ### physics

The force of friction between a crate and the floor it is sliding over depends on?
8. ### Physics

A factory worker pushes a 29.2kg crate a distance of 4.1m along a level floor at constant velocity by pushing downward at an angle of 28 degrees below the horizontal. The coefficient of kinetic friction between the crate and floor …
9. ### Physics

A factory worker pushes a 32.0 kg crate a distance of 4.9 m along a level floor at constant velocity by pushing downward at an angle of 32 ∘ below the horizontal. The coefficient of kinetic friction between the crate and floor …
10. ### physics

A 550 N crate rests on the floor. How much work in joules is required to move it at constant speed 7.0 m along the floor, against a friction force of 150 N?

More Similar Questions