Need help on Newton's Law Question and Determining speed

In summary, the question involves determining the speed of Iceman as he slides down a 1m inclined ice slide with a coefficient of kinetic friction of 0.100. The forces involved are gravity, normal force, and friction, and the problem can be simplified by drawing a free body diagram and setting the y force components to sum to zero. The given length of the incline is most likely 10.0 x 10^(-8) m instead of nm, and the normal force is perpendicular to the slide, not parallel.
  • #1
richvrd1
1
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<Mentor's note: moved from a technical forum, therefore no template>

My teacher made this question:

Iceman is sliding down a 10.0 x 10^(-8) nm ice that is inclined at 20.0 degrees with respect to the horizontal. Iceman is initially at rest. The coefficient of kinetic friction between iceman's feet and the ice is 0.100. Determine Iceman's speed at the bottom of the ice slide.

What I know:
1)There are 3 forces as he slides down this slide: force gravity going straight down, force normal which is parallel to the slide @ 20.0 degrees, and force friction which is in the opposite direction he slides down.
2)The slide is 1m.
3)ΣFnet= m ⋅ anet ... I then attempted to split it into x and y accordingly where ΣFnetx = m ⋅ anetx &
ΣFnety = m ⋅ anety
4) Force friction is equal to -(μ)Fn
5)Fnety= Fgy + Fn
 
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  • #2
Welcome to Physics Forums.
If you have not done so already, you should draw a free body diagram. And I would recommend drawing your +x axis in the direction of the downward slope of the incline, with your y-axis perpendicular to that. By doing that, you will only have an x component of acceleration, which should simplify the problem. Then the y force components will sum to zero, allowing you to find the normal force, which will allow you to find the friction force.

Seems very strange that the incline length is specified to be 10.0 x 10^(-8) nm. By the way, it looks like it should be +8.
Also, it was probably just misstated but the normal force is perpendicular to the slide, not parallel.
 

1. What is Newton's First Law?

Newton's First Law, also known as the Law of Inertia, states that an object at rest will remain at rest and an object in motion will remain in motion at a constant velocity, unless acted upon by an external force.

2. Can you explain the concept of inertia in relation to Newton's First Law?

Inertia is the resistance of an object to change its state of motion. According to Newton's First Law, an object will maintain its current state of motion unless an external force acts upon it. This means that a stationary object will remain stationary and a moving object will continue to move in the same direction and at the same speed, unless a force is applied to change its motion.

3. How do you determine the speed of an object using Newton's Second Law?

Newton's Second Law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This can be represented by the equation F=ma, where F is the net force, m is the mass of the object, and a is the acceleration. By rearranging this equation to solve for acceleration (a=F/m), and then using the equation v=u+at (where v is final velocity, u is initial velocity, a is acceleration, and t is time), you can determine the speed of an object at a given time if the net force and mass are known.

4. Can Newton's Third Law be applied to determine the speed of an object?

No, Newton's Third Law states that for every action, there is an equal and opposite reaction. This law describes the relationship between two objects exerting forces on each other. It does not directly relate to determining the speed of an object.

5. How does Newton's Law of Universal Gravitation relate to determining the speed of objects?

Newton's Law of Universal Gravitation states that any two objects in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. While this law does not directly relate to determining the speed of objects, it can be used to calculate the gravitational force between two objects, which can then be used in conjunction with Newton's Second Law to determine the acceleration and speed of the objects.

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