You want to push a 66-kg box up a 30° ramp. The coefficient of kinetic friction between the ramp and the box is 0.35. With what magnitude force parallel to the ramp should you push on the box so that it moves up the ramp at a constant speed?

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Physics - bobpursley, Thursday, February 16, 2012 at 5:04pm

You have to overcome friction and gravity

gravity down the plane:mg*SinTheta
friction: mg*mu*cosTheta

I know i posted this before earlier sorry about that but I really need help with it because its not working out please help

To determine the magnitude of the force parallel to the ramp needed to push the box up at a constant speed, you need to consider two factors: the force of gravity acting down the slope and the force of friction opposing the motion.

1. Calculate the force of gravity acting down the ramp:
The force of gravity can be determined by multiplying the mass of the object (66 kg) by the acceleration due to gravity (9.8 m/s²) and the component of gravity acting parallel to the ramp, which is the sine of the ramp angle (30°):
Force of gravity = mg * sin(30°)

2. Calculate the force of friction opposing the motion:
The force of friction can be determined by multiplying the coefficient of kinetic friction (0.35) by the perpendicular force exerted by the box on the ramp. The perpendicular force is the weight of the object (mg) multiplied by the cosine of the ramp angle (30°):
Force of friction = μ * (mg * cos(30°))

3. The force needed to push the box up the ramp at a constant speed is equal to the sum of the force of gravity and the force of friction:
Force needed = Force of gravity + Force of friction

Substituting the values into the equations:

Force of gravity = (66 kg) * (9.8 m/s²) * sin(30°)
Force of friction = (0.35) * [(66 kg) * (9.8 m/s²) * cos(30°)]

Once you have the values for the force of gravity and the force of friction, add them together to get the force needed to push the box up the ramp at constant speed.