Help please simple Physics frictionless crate on ramp problem Urgent?

In summary, the problem involves a 100 kg crate being pushed up a frictionless ramp at a constant speed. The force required to push the crate up the ramp is equal to its weight times the sine of the ramp angle. In order to find the correct answer, the force must be divided by the cosine of the ramp angle. The force on the crate from the ramp can be found by using the x and y components of the applied force and applying Newton's First Law in each direction.
  • #1
172
0
Help please! simple Physics frictionless crate on ramp problem! Urgent!?

A crate of mass m = 100 kg is pushed at constant speed up a frictionless ramp (θ = 30.0°) by a horizontal force F. What are the magnitudes of (a) F and (b) the force on the crate from the ramp?

So my teacher did this problem but I do not understand

here's what he did:

a) mg sin θ = 100(9.8)sin30 = 490 N (I understand this part)
490 / cos30 = 566N <--Why divide by cos 30 to get the correct answer?!?

b) N = mg cos θ + F sin θ
100(9.8)cos30 + 566sin30 = 1131N <--I do not understand part b) at all. Can someone explain step by step on what we are doing on part b).

help please!
 
Physics news on Phys.org
  • #2


help i have a test tmrw!
 
  • #3


Choose the x-axis as the axis parallel to the plane and the y-axis perpendicular to the plane. The applied force is horizontal and you can break it up onto its x and y components. Then use Newton 1 in the x direction and Newton 1 in the y direction.
 

1. What is the formula for calculating the force of friction in a frictionless crate on a ramp?

The formula for calculating the force of friction in a frictionless crate on a ramp is Ff = μN, where Ff is the force of friction, μ is the coefficient of friction, and N is the normal force.

2. How do you determine the coefficient of friction in a frictionless crate on a ramp problem?

The coefficient of friction can be determined by dividing the force of friction by the normal force. In a frictionless crate on a ramp problem, the coefficient of friction will always be zero, as there is no force of friction present.

3. Can you calculate the acceleration of the crate on the ramp without knowing the mass of the crate?

No, the mass of the crate is an essential component in calculating the acceleration. The formula for acceleration is a = F/m, where a is the acceleration, F is the net force, and m is the mass. Without knowing the mass, the acceleration cannot be accurately calculated.

4. How does the angle of the ramp affect the force of friction in a frictionless crate on a ramp problem?

The angle of the ramp does not affect the force of friction in a frictionless crate on a ramp problem. In a frictionless scenario, the force of friction is always zero, regardless of the angle of the ramp.

5. Is there any other factor that can affect the acceleration of the crate on the ramp besides the mass and net force?

In a frictionless crate on a ramp problem, the only factors that affect the acceleration are the mass of the crate and the net force applied to it. Other factors, such as the angle of the ramp or the coefficient of friction, do not have an impact on the acceleration in a frictionless scenario.

Suggested for: Help please simple Physics frictionless crate on ramp problem Urgent?

Back
Top