# Mechanics Study Guide

Topics: Mass, Newton's laws of motion, Force Pages: 3 (793 words) Published: November 15, 2013
﻿1.1 If the Sun should suddenly explode (it can’t) how long would it take for us to notice the event? *
According to scientists we have at least 5-6 million years before the sun would ever die out or explode. However if a phenominon like that were to occur there are diffent theories to what might happen. It would take light from the explosion eight minutes to travel the 93 million miles from the sun to the earth. However, Newton's Law of Gravity claims that Earth would suffer an immediate departature from its normal ellpitctal orbit. If this were to happen knowlege of the sun's explosion would be instant due to the sudden change in the gravitational force conducting the Earth's motion. 1.2 Convert the number of seconds in the day and the mass of the moon in kg, into scientific notation.

Seconds in a day: 8.64 × 10^4
Mass of moon : 7.34767309 × 1022 kilograms
1.3 Name Kepler's’ three laws and state them in your own words.*
The Law of Ellipses:
"The path of the planets about the sun is elliptical in shape, with the center of the sun being located at one focus." This law reveals that every planet will revolve in an elliptcal orbit arround the sun and that they will remain in a bounded state.

The Law of Equal Areas:
"An imaginary line drawn from the center of the sun to the center of the planet will sweep out equal areas in equal intervals of time." This law implies that when a planet is far away from the sun moves slowly and moves faster when it is closer to sun.

The Law of Harmonies:
"The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun. " infers that if the planet is distant away from sun the time period of it around the sun is greater and when the planet is further away the time period around the sun is lesser. 1.4 What is the length (in AU) of the semi major axis of a body that takes 72 years (Halley’s Comet) to orbit the Sun?

17.8 AU
1.5 Suppose...