What
liquid at room temp.
can make a cannon ball float?
Weight - net gravitational force on an object
| w | = | Fg | = | mg |
| (N) | (kg)(m/s2) |
g = acceleration due to gravity
Earth: g = 9.8 m/s2
Moon: g = 1.6 m/s2
slope = g
| g(m/s2) | = | Fg | (N) |
| m | (kg) |
Mass - amount of matter an object possesses
Weightless
Not Massless!
What is the relationship
between mass and distance?
Choice 1 - Mass is not affected by distance (only weight)
1 kg ≈ 2.2 lbs
1 lbs ≈ 5 N
Average senior weighs
120 lbs - 600 N
Finding acceleration due to gravity using weight
Ex) A satellite having a mass of 25. kg experiences a gravitational force of 200. N. Find the acceleration due to gravity at this location.
Ex) A satellite having a mass of 25. kg experiences a gravitational force of 200 N. Find the acceleration due to gravity at this location.
| g(m/s2) | = | Fg | (N) |
| m | (kg) |
a = 8 m/s2
Ex) A rocket weighs 18,000 N at the earth's surface. If the rocket rises to a height where its distance from the earth is 3 earth radii, its weight will be ...
When an object is on the
earth,
it is one earth radius away.
| F= | Gm1m2 |
| r2 |
Distance from earth to rocket triples so, ....
....weight is 1/9 as great
Galaxy Formation
- Computer Simulation - NASA
Walking on the Moon - NASA