Physics Revision

Question 1

What force acts upon the rocket during take off?

Answer 1

Thrust

Question 2

Forces that keep a satellite in orbit…

Answer 2

Velocity and gravitational pull from the earth.

Question 3

Name the three different orbits

Answer 3

Geostationary orbit, Low Polar orbit and Low Earth orbit.

Question 4

Name three uses of satellites…

Answer 4

Telecommunications, navigation, monitoring the weather.

Question 5

Explain the Big Bang Theory…

Answer 5

The Big Bang theory was a theory that earth started from a very small fireball of infinite density that exploded and intense heat and light flew out. After 300,000 years, temperatures dropped enough for atoms to form. Clouds of hydrogen and helium gas also formed. The universe started expanding. Several billion years later matter began to contract creating stars and galaxies.

Question 6

Give a strength and a weakness of the expanding universe balloon model.

Answer 6

Strength: Gives a good visual idea of the universe expanding and represents something we cannot see directly.
Weakness: The balloon has a limit when it pops.

Question 7

When do scientists use mathematical models?

Answer 7

When its not possible to do an experiment to collect data.

Question 8

Three factors needed for there to be a chance of life existing somewhere other than the earth.

Answer 8

Right temperature, liquid water, atmosphere with oxygen.

Question 9

Suggest why it is likely that there is life in other places in the Universe.

Answer 9

There are billions of planets in the Universe, habitable zones have been found with right temperature, liquid water, atmosphere with oxygen.

Question 10

Which parts of the Earth do these satellites pass over?

Answer 10

Geostationary orbit: Equator
Low Polar orbit: North and South Pole
Low Earth orbit: Any

Question 11

How long does it take these satellites to complete one orbit?

Answer 11

Geostationary: 24 hours
Low Polar: Less than 24 hours
Low Earth: Between 90 minutes and 2 hours

Question 12

Does the satellite stay above the same point on the earth all the time?

Answer 12

Geostationary: Yes
Low Polar: No
Low Earth: No

Question 13

What are some risks of space missions?

Answer 13

Solar flare, top of rocket could explode, rely on parachutes to slow their descent.

Question 14

What is Solar Flare?

Answer 14

Process that produces a large amount of radiation emitted by the sun.

Question 15

One benefit of a space programme.

Answer 15

Health and medicine

Question 16

Old theories…

Answer 16

People in India believed the earth was flat and that it was supported by 12 pillars.
People in Thailand believed the earth was supported by the back of a turtle.
People in Greece believed the earth is the centre of the Solar System.

Question 17

What was the Geocentric model?

Answer 17

A theory that the earth is the centre of the Solar System and the planets and the sun were revolving around it.

Question 18

What is the heliocentric model?

Answer 18

A theory that the Sun is at the centre of the Solar System and the planets revolve around it.

Question 19

What is accuracy?

Answer 19

The accuracy of a measurement is how close a result comes to the true value.

Question 20

What is precision?

Answer 20

Precision is how consistent the results are when measurements are repeated.

Question 21

What is repeatable

Answer 21

A measurement is repeatable if the same person repeats the experiment using same same method and same equipment and gives similar results.

Question 22

What is reproducible?

Answer 22

A measurement is reproducible if Another person can get the same results.

Question 23

What is the independent variable?

Answer 23

Thing we change in experiment

Question 24

What is the dependent variable?

Answer 24

Measure variable

Question 25

What is the control variable?

Answer 25

Thing we keep the same

Question 26

What is the resolution of a measuring instrument?

Answer 26

Resolution is the smallest change in the quantity being measured that can be detected by an instrument.e.g. a typical mercury thermometer will have a resolution of 1°C, but a typical digital thermometer will have a resolution of 0.1°C.