We are given a box that slides up a ramp. To determine the force of friction we will use the following relationship:
Where.
To determine the Normal force we will add the forces in the direction perpendicular to the ramp, we will call this direction the y-direction as shown in the following diagram:
In the diagram we have:
Adding the forces in the y-direction we get:
Since there is no movement in the y-direction the sum of forces must be equal to zero:
Now we solve for the normal force:
To determine the y-component of the weight we will use the trigonometric function cosine:
Now we multiply both sides by "mg":
Now we substitute this value in the expression for the normal force:
Now we substitute this in the expression for the friction force:
Now we substitute the given values:
Solving the operations:
Therefore, the force of friction is 15.01 Newtons.
Answer:B,C,D
Explanation:
Thermodynamic efficiency is given by
efficiency can be increased by Keeping 
constant and increasing 
Keeping constant and decreasing 
by increasing 
by decreasing 
ratio
Answer:
50 N
Explanation:
Since the refrigerator doesn’t move, that means the force of friction equals the amount of force the child exerts on the fridge. If the friction force were greater than the force by the child, the fridge would start accelerating towards the child. If it were less than the force the child exerted, the fridge would start accelerating away from the child. Therefore, the net force must be 0, in this case, the friction force is equal to the force the child exerted, for it to stay at rest (as Newton’s First Law stated).
I hope this helps! :)
They are fused in the core of the star due to great pressures and temperatures. They are made all the way through iron. At that point the star dies. If it is a really large star it will become a supernova when it dies, creating all of the elements beyond iron as well, but only in its death. No star can create anything beyond iron in its life cycle
