Physics - Activity

Question 1

What does our solar system contain?

Answer 1

The sun, eight planets, dwarf planets, natural satellites (moons)

The solar system consists of various celestial bodies including the sun at its center.

Question 2

What is the name of the galaxy that our solar system is part of?

Answer 2

Milky Way galaxy

Question 3

Define nebula.

Answer 3

Cloud of gas and dust

Question 4

Define protostar.

Answer 4

A hot dense mass formed by increasing gravity

Question 5

What is a main sequence star?

Answer 5

A star undergoing nuclear fusion of hydrogen into helium, stable due to balanced forces from outward pressure and gravity

Question 6

What initiates the formation of all stars?

Answer 6

Gravity pulls a cloud of dust and gas together, increasing density, pressure, and temperature until nuclear fusion occurs

Question 7

Fill in the blank: Fusion reactions lead to an equilibrium between the _______ of a star and the _______ of a star due to fusion energy.

Answer 7

gravitational collapse, expansion

Question 8

What determines the life cycle of a star?

Answer 8

The size (mass) of the main sequence star

Question 9

List the stages in the life cycle of a star.

Answer 9

• Protostar
• Main sequence star
• Red giant star
• Red super giant star
• Supernova
• Neutron star
• Black hole
• Black dwarf

Question 10

How are elements formed in stars up to and including iron?

Answer 10

Fusion reactions in stars

Question 11

How are elements heavier than iron formed?

Answer 11

During a supernova

Question 12

Explain why heavier elements are formed and how they are dispersed.

Answer 12

The temperature and pressure in a supernova are so large that nuclei are forced together, and the explosion disperses elements throughout the universe

Question 13

What do planets orbit?

Answer 13

Sun

Question 14

What do satellites orbit?

Answer 14

Planets

Question 15

How do satellites and planets maintain their orbit?

Answer 15

Gravity

Question 16

What is a similarity between artificial satellites and moons?

Answer 16

Both orbit a planet

Question 17

What is a difference between artificial satellites and moons?

Answer 17

Moons are natural, satellites are man-made

Question 18

What is the shape of the orbit of a planet around the Sun?

Answer 18

Circular/Elliptical

Question 19

Describe the difference between speed and velocity for an object in a circular orbit.

Answer 19

Speed remains the same, but velocity changes due to constant change in direction

Question 20

What happens to the orbit if the speed changes?

Answer 20

The radius would change

Question 21

Define centripetal force.

Answer 21

A force acting towards the center which causes an object to keep moving in a circular path

Question 22

How are radius and speed related in an orbit?

Answer 22

The greater the radius, the slower the speed

Question 23

How can you keep an orbit stable when you change the radius?

Answer 23

Change the speed as well

Question 24

Describe and explain red-shift.

Answer 24

Red-shift is the observed increase in wavelength of light towards the red end of the spectrum due to an object moving away

Question 25

Explain the link between the distance of galaxies from us and red-shift.

Answer 25

The further away they are, the bigger the red-shift

Question 26

Describe the big bang theory.

Answer 26

The universe started from a very small region that was hot and dense and has been expanding ever since

Question 27

What evidence supports the big bang theory?

Answer 27

• Red-shift: indicates the universe is expanding
• Change of galaxies’ speed: provides evidence of an expanding universe as further galaxies recede faster

Question 28

How is a theory developed?

Answer 28

Scientists use observations, look for patterns in data, and form predictions

Question 29

What are some examples of things we do not understand about the universe?

Answer 29

• How the increase in expansion of the universe is occurring
• Dark mass
• Dark energy