Circular Motion Help: Solve Physics Homework

In summary, the conversation discusses questions related to physics homework. The first question is about the speed difference between the top and bottom of a 300m-tall tower on the equator. The second question involves finding the speed of a child on a 5m-diameter merry-go-round before it slows down and stops in 20s. The third question is about the number of revolutions per second an electron makes in the Bohr model of the hydrogen atom. The conversation also includes a question about the relationship between rotational and linear speed.
  • #1
thebigeis
15
0
I am having some trouble with my physics homework.

#1) A 300m-tall tower is built on the equator. How much faster does a point at the to of the tower move than a point at the bottom?

#2) A 5m-diameter merry-go-round is initually turning with a 4.0s perio.d It slow down and stops in 20s. Before slowing, what is the speed of a child on the rim?
 
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  • #2
I am having some trouble with my physics homework.

#1) A 300m-tall tower is built on the equator. How much faster does a point at the to of the tower move than a point at the bottom?

#2) A 5m-diameter merry-go-round is initually turning with a 4.0s period It slow down and stops in 20s. Before slowing, what is the speed of a child on the rim?

#3) In the Bohr model fo the hydrogen atom, an electron (mass m = 9.1X10^-31 kg) orbits a proton at a distance of 5.3X10^-11m. The proton pulls on the electron with an electric force of 8.2X10^-8N. How many revolutions per seconds does the electron make?

For #2, I just don't even know how to get the angular velocity with only the period and 5m diameter information to get the non-uniform circular motion velocity. For #3, I don't know how to derive the period (T) out of any of the information they give me. I'm new to this subject, can anyone enlighten me?
 
Last edited:
  • #3
I just got #1.
 
  • #4
For part 1, there are 2 questions you need to answer. How far does the top travel, How long does it take.

#2. What is the relationship between rotational and lineral speed?
 
  • #5
The fact that the merry go round slows to a stop is unimportant to the question. The general principal of speed applies here. think, what is the distance covered in one revolution of a circle? (It has a name, begins with "C"). How much time does it take to complete one revolution?
 
  • #6
In one revolution fo a circle is equal to 2pi. And in the problem it says one period is 4s. And if I'm getting this straight, which I'm not, 2pi/4 would be the rev/s?
 
  • #7
I got #1, but for number 2, I don't knwo the relationship between rotational and linear speed...
 

FAQ: Circular Motion Help: Solve Physics Homework

What is circular motion and how is it different from linear motion?

Circular motion is the movement of an object along a circular path. Unlike linear motion, where an object moves in a straight line, circular motion involves a constant change in direction, resulting in a circular path.

How do you calculate the velocity and acceleration of an object in circular motion?

The velocity of an object in circular motion can be calculated using the formula v = rω, where v is the velocity, r is the radius of the circular path, and ω is the angular velocity. The acceleration can be calculated using the formula a = rω², where a is the acceleration and ω is the angular velocity.

What is centripetal force and how does it relate to circular motion?

Centripetal force is the force that keeps an object moving in a circular path. It acts towards the center of the circular path and is always perpendicular to the object's velocity. In circular motion, centripetal force is equal to the mass of the object times its centripetal acceleration.

How does the mass of an object affect its circular motion?

The mass of an object does not affect its circular motion. As long as the object is moving at a constant speed and is subject to the same centripetal force, its mass will not change the circular path it follows. However, a larger mass may require a greater centripetal force to maintain the circular motion.

Can you explain the concept of tangential velocity in circular motion?

Tangential velocity is the velocity of an object along a tangent to its circular path. It is always perpendicular to the centripetal force and is constant in magnitude if the object is moving at a constant speed. It is calculated using the formula v = rω, where v is the tangential velocity, r is the radius, and ω is the angular velocity.

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