1) Acceleration of the sled
The acceleration of the sled is given by the net force acting in the direction parallel to the incline. There are two forces acting along this direction: the component of the weight parallel to the ramp (downward) and the friction (upward). Therefore, the net force acting in this direction is

And the acceleration is given by Newton's second law:

2) Normal force
The normal force acting on the sled is equal to the component of the weight perpendicular to the incline, therefore:

Answer:
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second. So in one year, it can travel about 10 trillion km. More p recisely, one light-year is equal to 9,500,000,000,000 kilometers
Answer:
a) F₁ = F₂, F₃ = F₄, b) the correct answer is 3
Explanation:
a) In this exercise we have several action and reaction forces, which are characterized by having the same magnitude, but different direction and being applied to different bodies
Forces 1 and 2 are action and reaction forces F₁ = F₂
Forces 3 and 4 are action and reaction forces F₃ = F₄
as it indicates that the
b) how the car increases if speed implies that force 1> force3
F₁ > F₃
therefore the correct answer is 3
Let us reject some answers. AM and FM radio waves do not interfere. Am are an orders of magnitude larger than FM waves. FM waves belong to microwaves, a subcategory of radiowaves while AM does not. Similarly, AM and TV have not the same, because TV uses a subset of the frequencies used in FM. The correct answe is that CB radios and submarine communication happen at the same wavelengths/frequencies, namely low frequency radiowaves.
Just because the book is moving doesn't tell you anything about the forces on it, or even whether there ARE any.
Just look at Newton's first law of motion, and this time, let's try and THINK about it too. It says something to the effect that any object continues in constant, uniform MOTION ..... UNLESS acted on by an external force.