How much force is needed to lift 25 lbs? Also, how much force is necessary to push 150 lbs up a ramp 3ft high?

Question

I'm not sure if there is even enough information here to answer the questions, as its been a while since i've studied physics.

Answer 1

25 lbs is 11.36 kg so F=ma = 11.36*9.8 = 111.33 N is required to exactly balance the force created by gravity. Anything greater than this and the mass will begin to accelerate upwards.

The amount of force needed to push something up a ramp is proportional to the sine of the angle the ramp makes with the floor (neglecting any kind of friction)


Doug

Answer 2

Why is 3 feet important? Sounds like maybe you want the amount of energy (work) required to lift this 25 lbs.

If so, energy=force*distance, with energy in Joules, force in Newtons and distance in meters.

one foot=0.3048 meters
one pound force=4.448 Newtons (N)

The power required is given by power=force*speed. A Watt is a Joule/second, SI unit of power. speed is in meters/sec

don't forget about friction if this is a real-world problem.
There are two kinds:
static
kinetic

the static coefficient of friction is about how much friction will fight against starting the thing moving. kinetic once its in motion.
neither coefficient has any units at all.

Answer 3

To lift 25 lbs, you need a force slightly greater than 25 lbs.

As far as the ramp is concerned, we need more information...such as the length of the ramp to determine the angle of the inclined plane.

Answer 4

In an ideal environment, moving things vertically against gravity requires work, and moving things horizontally does not. So, IN THEORY, it doesn't matter whether you lift something directly or use a ramp of any slope. It's the same amount of work either way.

Answer 5

25 pounds is needed to lift 25 pounds, well maybe a teeny weenie bit more than 25...
As for the ramp, it depends on the coefficient of friction between it and the weight and the angle of the ramp...