Science Chapter 3

Question 1

What happens if a rock is only standing there by itself on the ground and no push/pull is acting on the rock.

Answer 1

The force of the weight, contact force remains the same

But if a wind happens to blow, the force of the wind will act on the rock on the direction the wind is blowing, there will be friction aswell. But the pushing force are usually larger than the friction

Question 2

What makes an object slow down?

Do you have an example of this?

Answer 2

Unbalanced or unequal forces can make an object slow down. For example, When the parachute first opens, the forces are unbalanced, this can make the object slow down. When the object slows, the air resistance decreases, so the forces becomes balanced again and fallsa t constant speed.

Question 3

What makes an object change direction?

Answer 3

unbalanced forces can also make objects change direction when the force is applied to the object in a direction.

Question 4

How to calculate distance

Answer 4

time multiplys speed

Question 5

How to calculate the rate of the time

Answer 5

distance divided by speed

Question 6

how to calculate speed

Answer 6

Distance divided by Time

Question 7

What do you call an object that turns

Answer 7

lever

Question 8

what do you call the point around the lever that turns

Answer 8

pivot

Question 9

Explain what is moment

Answer 9

A force that describes its the turning effect of force

Question 10

How to calculate moment

Answer 10

force x distance

Question 11

What is the unit of moment

Answer 11

Nm (Newton Metre)

Question 12

Marcus weights 600N and sits at a distance of 2m from the pivot of a seesaw.Arun weights 800N and where should Arun sit to make sure the seesaw is balanced?

Answer 12

600N x 2 = 1200Nm
1200/800=1.5M

Question 13

How to calculate pressure

Answer 13

force divided by area

Question 14

What is the unit of pressure

Answer 14

N/m^2 ( newtons per metre squared)

Question 15

How do pressure work

Answer 15

The force and the weight of the object is focused on the contact area. Thus, if the contact area is smaller, the pressure is larger because of all the weight and force focused on that tiny area

Question 16

How do pressure in gases work
(In Balloons) (and how does it become bigger)

Answer 16

Particles in gas move randomly and collide with walls of the CONTAINER. the CONTAINER is the BALLOON.

Everytime a gas particle collides with the wall of the container, the particle exerts a small force on the wall.The more particles there are in the gas, the more collisions happen.

As force is exerted on an area, the force causes pressure. Therefore, the pressure inside the balloon gets bigger as you blow it.

Question 17

Explain the theory behind pressure and depth in gases.

Answer 17

The atmospheric pressure at sea level is at the highest.

As you go higher in the atmosphere, the number of particles of air decreases, the concentration of gas particles decreases

Question 18

What is altitude

Answer 18

Altitude is height above sea level

Question 19

If air is pumped out of an object, what happens?

Answer 19

The pressure inside the object is low, but the object might remain in a crushed shaped because of the atmospheric pressure crushing it

Question 20

Explain what is Diffusion

Answer 20

diffusion is the movement of particles from an area where they are higher in concentration to an area of lower concentration.

Question 21

Explain what is concentration of particles

Answer 21

Concentration is the number of particles in a volume.

Question 22

What affects the speed of diffusion?

Answer 22

The bigger difference in the concentration of particles, the faster they diffuse

Temperature, they make particles move and spread out faster

Question 23

Does pressure increase within depth?

Answer 23

yes

Question 24

Does pressure act in all directions?

Answer 24

yes

Question 25

Explain the properties of Pressure

Answer 25

It increases with depth, the deeper a liquid , the greater the weight above and higher the pressure.

Pressure depends upon the density of the liquid. The more dense a liquid the higher the pressure at any given depth

Pressure doesn’t depend on the shape of the container. The pressure at any particular depth is the same whatever the shape or width of the container.

Question 26

Why do dams have a thicker base

Answer 26

Pressure increases with depth, the deeper a liquid, the greater the weight above and so the higher pressure.

Therefore, Dams have a thick base to protect against the pressure