# Midterm Assesment Flashcards

1
Q

Why do we have day and night?

A

Because the Earth rotates on its axis. It takes 24 hours to complete a full rotation which is why the day is 24 hours long.

2
Q

What makes a year 365 days?

A

This is because to complete a full rotation around the sun it takes 365 days

3
Q

What makes summer different from winter?

A

In the winter we are facing further away from the sun so the light is less concentrated in us. In the summer we are facing the sun so the light is more concentrated.

4
Q

When it is winter in Britain, what season is it in Australia, why?

A

In the winter the northern hemisphere it’s facing away from the sun but the lower hemisphere is facing towards the sun so it is summer for them and winter for us.

5
Q

What does a satellite orbit? What is the shape of that orbit?

A

Satellites orbit planets. There are natural satellites called moons and there are artificial satellites used for communication e.g. TV. They orbit in a slightly elliptical orbit

6
Q

What does a comet orbit? What is the shape of that orbit?

A

Comets orbit in a very elliptical orbit around the sun. The sun is not at the centre of their orbit,

7
Q

Why are the star in May different from the stars we see in December?

A

As the earth revolves around the sun the position of the earth changes and this creates different view of the night sky.

8
Q

What 3 things about an object can a force change?

A

Shape, speed and the direction of travel

9
Q

Name 3 forces acting in this room and one that doesn’t.

A

Gravity, contact force, friction and upthrust.

10
Q

What is Newton’s first law of motion?

A

An object at rest remains at rest and an object in motion remains in motion at a constant speed in a straight line unless acted on by an unbalanced force.

11
Q

A box has a 5N force acting on it pushing it to the left and a 4N force acting on it pushing it to the right. Calculate the force acting on it.

A

1N to the left

12
Q

Now both forces act downwards. What is the new resultant force?

A

9N

13
Q

Why are racing cars flat and smooth?

A

So there is less air resistance pushing it back and so it can glide easily through the air.

14
Q

If I want to reflect infra-red radiation when I go outside, what colour should my coat be?

A

Silver

15
Q

Removing the air from inside something creates a vacuum. Why is this hard to do in the lab?

A

Forming a perfect vacuum is impossible because no device can removes very single atom or molecule from a space. So it’s impossible to create a full vacuum.

16
Q

What causes water pressure on your goggles when you go underwater?

A

The deeper you go under the sea, the greater the pressure of the water pushing down on you as all the weight of the water above is being pushed on you.

17
Q

Why does a marshmallow grow when put in a vacuum?

A

In a vacuum most particles are removed from the air and the particles compact the marshmallow so when they are released the marshmallow is not compacted and doesn’t have the pressure particles pushing on it.

18
Q

If I put an object on a newtonmeter and get a reading of 32N, did I measure weight or mass?

A

Weight

19
Q

Going to the moon would change which one: weight or mass? Why?

A

Weight because wight is decided on how much gravity is there and mass is the body amount based that wont change on a different planet as it doesn’t use gravity to measure it.

20
Q

On Earth, what is gravitational field strength, g?

A

10 N

21
Q

On Earth, what does a mass of 12kg weigh?

A

120 N

22
Q

On Jupiter, where g=22 N/kg, what does the same mass weigh?

A

12kg

23
Q

What is the mass of an object with weight 4.5N on Earth

A

0.45kg

24
Q

Where would I go if I wanted to be weightless, and why?

A

Space because there is no gravity in space and do have wight there needs to be gravity

25
Q

What is the speed of an object that travels 100 metres in 20 seconds?

A

5 m/s

26
Q

What is the speed if it travels 100 metres in 1 minute?

A

1.66 m/s

27
Q

What equipment is needed to measure, what units: Force? Temperature?
Distance?
Time?

A
1. Newton Meter, newtons
2. Thermometer, Celsius
3. Meters , ruler, meter stick
4. Seconds , stop watch
28
Q

What is streamlining?

A

A form that presents very little resistance to a flow of air or water and increasing speed and ease of movement.

29
Q

What is a resultant force?

A

A resultant force is a system of forces acting on an object where the difference between the forces is the resultant force.

30
Q

A

31
Q

What is the formula of finding pressure?

A

Pressure (pascal) = force (N)
————
area (m2)

32
Q

What is the formula to find mass?

A

Mass (kg) = weight (N)
—————
gravitational force (10N/kg)

33
Q

What is the formula to finding average speed?

A

Average speed (m/s) = distance (M)
——————-
time (S)

34
Q

What causes pressure in terms of atoms and particles?

A

Pressure comes from the collisions of particles with the container.