Explore BrainMass
Share

# General questions: Six questions to learn concepts

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

1. The Moon is centripetally accelerating towards the Earth. Explain why it is not getting closer to the Earth.

2. Why is it easier to hold a 10lb weight next to your body instead of with your arm outstretched?

3. When you design a building in an earthquake region, how should the natural frequencies of oscillation of the building compare to the typical earthquake frequencies and why? Explain.

4. What is the purpose of frets on a guitar? In terms of frequency of the vibration of the strings; explain their use.

5. When you inhale helium and speak, your voice becomes far higher in pitch.

6. You hold a tuning fork in front of you in a stationary position. Another tuning work of the same frequency is moving toward you at a fair speed. Explain what you hear and why.

https://brainmass.com/physics/torques/general-questions-questions-learn-concepts-287458

#### Solution Preview

1. The Moon is centripetally accelerating towards the Earth. Explain why it is not getting closer to the Earth
The acceleration of a body is the rate of change of its velocity. Thus if the velocity of a body changes with time, it is accelerating.
Now velocity is a vector quantity. A vector is represents the magnitude and direction both of the quantity. Such quantity will change by changing its magnitude, its direction or both.
When a body moves in a circular path with constant speed, the magnitude of its velocity remains constant while its direction continuously changes. Thus the velocity vector changes in direction. This corresponds to the acceleration of the body. This acceleration is always towards the center of the circular path and that is why called centripetal acceleration.
To produce acceleration, a force is required. The component of the force along the direction of motion changes magnitude of velocity while the component of force perpendicular to the direction of motion changes direction of motion only.
The moon moves in a circular path round the earth. The gravitational force experienced by the moon behaves as the centripetal force which produces centripetal acceleration which is changing the direction of motion just enough to keep it in a circular path with the distance between them as radius and hence the distance of the moon from the earth does not changes.

2. Why is it easier to hold a 10lb weight next to your body instead of with your arm outstretched?

A ...

#### Solution Summary

Six questions related to centripetal force, torque, vibrations and sound are explained.

\$2.19