Newton's 2nd Law & Inclined Ramp

In summary, the conversation is about two problems, one involving an astronaut's weight in space and the other involving a box on an inclined ramp. The astronaut's weight is discussed in relation to the mass of two stars and the concept of infinite space. For the box on the ramp, the mu of k is calculated and the acceleration for a mass of 175 kg is found. The individual is struggling with understanding how to find the force of friction in part b and suggests using a free body diagram for a clearer understanding of the forces involved.
  • #1
Mayy
3
0
Well these two problems were from my quiz, and if I don't find out how to solve them soon, I'm going to spend my whole weekend thinking about them. D8 I'll try to remember the problems as best I can.

1) An astronaut is in space, in the midpoint of two stars that have the same mass. If all other stars are an infinite space away, how much does the astronaut weight? Explain.

2) A 75 kg box is on an inclined ramp that has an angle of 25 degrees. Its acceleration is 3.6 m/s/s.
a) Find mu of k between the box and ramp.
b) If the mass is 175 kg, what is its acceleration?

The answers to #2 are (a) .061, (b) 1.54 m/s/s
I just don't understand how to do part b. I got as far as finding sin, cos, and Fn, but I got stuck at finding Force of friction. I gave part a, just in case it's needed to solve b.
 
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  • #2
Please show your work and then we can see where you are getting stuck.

For #2, part b presumably uses the same mu as you found in part a.
 
  • #3
Always use a free body diagram for the questions like 1.Where there is a force acting on something, so you can have a clear map of forces..
 

1. What is Newton's 2nd Law?

Newton's 2nd Law, also known as the Law of Force and Acceleration, states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This means that the more force applied to an object, the more it will accelerate, and the greater the object's mass, the less it will accelerate.

2. How is Newton's 2nd Law applied on an inclined ramp?

When an object is placed on an inclined ramp, the force of gravity acting on it is split into two components: the normal force (perpendicular to the ramp) and the parallel force (along the ramp). According to Newton's 2nd Law, the parallel force is responsible for the object's acceleration down the ramp, while the normal force counteracts the force of gravity and prevents the object from sinking into the ramp.

3. What is the equation for Newton's 2nd Law?

The equation for Newton's 2nd Law is F=ma, where F is the net force applied to an object, m is the mass of the object, and a is the resulting acceleration. This equation can be rearranged to solve for any of the variables, such as F=ma or a=F/m.

4. How does the angle of the inclined ramp affect the acceleration of an object?

The angle of the inclined ramp affects the acceleration of an object by changing the magnitude of the parallel force. As the angle increases, the parallel force decreases, resulting in a slower acceleration down the ramp. This can be seen in the equation F=mg sinθ, where θ is the angle of the ramp. As θ increases, sinθ decreases, resulting in a smaller parallel force.

5. Can Newton's 2nd Law be applied to objects on a horizontal surface?

Yes, Newton's 2nd Law can be applied to objects on a horizontal surface as well as inclined ramps. In this case, the parallel force is equal to the force of friction acting on the object, since there is no slope to create a normal force. The resulting acceleration of the object will depend on the magnitude of the applied force and the coefficient of friction between the object and the surface.

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