Gravity Test

Force

A push or pull on an object

Acceleration

that occurs due to the force of gravity acting on an object's mass.

Force and acceleration

Directly proportional

g

• acceleration of gravity

G

gravity constant

Law of Universal Gravitation (F=Gmm/d^2)

• F = force of gravity (Newtons)

• G = Gravity constant (6.67 x 10^-11 N x m^2/kg^2)

• M1 and m2 = mass (kg)

• d= distance (m)

Inverse square law

• When the distance between objects increases by x, the gravitational force decreases by 1/x^2

  • Ex: Distance doubles, and gravitational force decreases by ¼

• When the distance between objects decreases by 1/x, the gravitational force increases by x^2

  • Ex: distance decreases by 1/100, force increases by 10,000

The gravitational force on different objects on the same planet

• different and is directly proportional to mass

Acceleration of different masses on the same planet

• the same in the absence of air resistance

Force of gravity between two objects

• the same, effect of the force may differ

  • For example, the force of gravity between us and the Earth affects us because our mass is small, but the same force does not change the Earth due to its large mass

Mass

• how many particles inside an object (kg)

Weight

 The effect of gravity on an object (N)

W=mg

• W = weight (N)

• M = mass (kg)

• g = acceleration of gravity (m/s^2)

v=gt

• v=velocity

• g=acceleration of gravity

• t=time

h = ½ gt²

h = vertical distance (m)

g = gravitational acceleration

t = time (sec)

Projectile motion

Independence of horizontal and vertical motion

• Do not affect each other

•  D =rt = used for horizontal motion

• v=gt = used for vertical motion

Horizontal velocity does not change because there is no force acting on it

Horizontal acceleration is 0 because once the object is released, no forces is acting upon it horizontally

Vertical velocity does change

Vertical acceleration does not change

Horizontal projectile

• Mass does not affect its motion, because everything on Earth accelerates the same amount 

• No matter how fast you throw it, the time doesn't change, the distance does change

• The time and distance will change depending on how high you throw an object

Orbits of moons/satellites

• Depending on the planet’s gravity, the moon’s or satellite’s size, and other gravitational factors

  • The closer a moon or satellite is to a planet, the closer it orbits, and this could result in it getting pulled into the planet and colliding

  • If a moon or satellite is too far away from the planet, this could result in it getting pulled by another planet or object’s gravity

 As the net force increases

 so does the acceleration

• Any two objects in the universe

attract each other

More mass

= more gravitational pull

Less mas

•  more acceleration