Gravitational field ,Satellite motion and Torques

Question 1

what is a Torque?

Answer 1

a turning force

a torque is applied when a force acts at a posistion othern than the centre of mass or fixed axle

Question 2

Forces produce translational acceleration ,what do Torques produce?

Answer 2

Ratational accelartion

Question 3

Torque does the same thing for rotational movement as force does for translational movement.

Answer 3

1.Forces causes translationalacceleration
2.Torques cause rotationalacceleration

Question 4

what is the Pivot point

Answer 4

The axis about which the object rotates

Question 5

what is a lever arm?

Answer 5

the distance from the pivot point to where the force is applied

Question 6

what is the perpendicular distance

Answer 6

The shortest distance from the pivot point to the line of action

Question 7

explain why a saucepan with a longer length handle would be harder to keep horizontal to avoid spilliing water compared to one with a smaller handle

Answer 7

The saucepan with the longer handle will be harder to keep horiontal .This is because the weight of the water is acting further away from the hand which is conisdered as the pivot point .Since distance between the pivot point and the weight force is increased the Torque is increase which makes it more likely for the saucepan to tip

Question 8

what happens when the pivot point is increased

Answer 8

the Torque also increases

Question 9

List three changes that could be made to increase the amount of TORQUE applied to an object

Answer 9

Increase the force applied to the handle
decreases the angle of the force
Push higher up on the handle

Question 10

lesson outcomes for Gravitational field

Answer 10

1.all objects with mass attract one another with gravitaional forces ;The magnitude of this force can be caluculated using Newton’s Law of Universal Gravitation
2.objects with mass produce a gravitational field in space that surrounds them;Field theory attributes the Gravitational force on an object to the presence of a gravitationaal field
3.gravitational field strenght is defined as the net force per unit mass at a particular point in the field

Question 11

Gravitational fields

Answer 11

• Fields are used in physics to represent non-contact forces
  1. Electric Fields
  2. magnetic fields
  3. gravitational fields

all objects with mass produce a gravitational field

Question 12

Gravitational field lines show;

Answer 12

1.direction force (using arrows)

2.Strength of force(using density of lines)

Question 13

Gravitational fields on the earth

Answer 13

go down torwards the ground and are even spaced

Question 14

Newton’s Law of Universal Gravitation

Answer 14

r

Question 15

Remember for Gravitational forces

Answer 15

The gravitational force attracting two objects is symmetrical
the resulting acceleration is not

Question 16

acceleration of Planets

Answer 16

Question 17

What is Gravitational field strength ?

Answer 17

the net force per unti mass caused by the grav field=GM/r^2

It is equivalent to the acceleration that an object will undergo in that Gravitaional field

Question 18

For gravitational fields questions when asked for altitude use…..

Answer 18

distance found -radius of the earth
(the total distance from centre to center- radius of the thing u got)

Question 19

test advice

Answer 19

be familiar with the terminology in physics (Gravitational field strength,Garviational forc

Question 20

Explain why both mass and density affect the gravitational field strength at the surface of any celestial body.

Answer 20

A larger mass increases the gravitationali field strength .A denser celesital body has a small radius compared to a less dense body of the same mass.A denser body therefore increases the gravitational field strength near the surface

Question 21

Explain why gravitational field strength does not depend on the density of the celestial body as the altitude increases.

Answer 21

when applyign the grav field stregth formula the mass of the entire body and R is the distance from the centre of the body’s mass.It does not matter how dense the body is when far away from the centre .Being denser means that it’s possible to get closer to the centre cause the mass is within a smaller value

Question 22

what is a geosynchronus orbits

Answer 22

A geosynchronus satelite has an orbital period which matches the Earth’s Rotational period (24hrs)
* useful for keeping the satelite above the same region

use kelpers law for orbital froblems and FC=Fg to derive kelps laws

Question 24

How to calculate velocity of a satellite orbiting earth

Answer 24

V=square root of GMof earth/r
Note r= the sum of the radius of earth and the height above the earth