Science Chapter 3 Flashcards
Ace Science
What happens if a rock is only standing there by itself on the ground and no push/pull is acting on the rock.
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
What makes an object slow down?
Do you have an example of this?
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.
What makes an object change direction?
unbalanced forces can also make objects change direction when the force is applied to the object in a direction.
How to calculate distance
time multiplys speed
How to calculate the rate of the time
distance divided by speed
how to calculate speed
Distance divided by Time
What do you call an object that turns
lever
what do you call the point around the lever that turns
pivot
Explain what is moment
A force that describes its the turning effect of force
How to calculate moment
force x distance
What is the unit of moment
Nm (Newton Metre)
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?
600N x 2 = 1200Nm
1200/800=1.5M
How to calculate pressure
force divided by area
What is the unit of pressure
N/m^2 ( newtons per metre squared)
How do pressure work
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
How do pressure in gases work
(In Balloons) (and how does it become bigger)
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.
Explain the theory behind pressure and depth in gases.
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
What is altitude
Altitude is height above sea level
If air is pumped out of an object, what happens?
The pressure inside the object is low, but the object might remain in a crushed shaped because of the atmospheric pressure crushing it
Explain what is Diffusion
diffusion is the movement of particles from an area where they are higher in concentration to an area of lower concentration.
Explain what is concentration of particles
Concentration is the number of particles in a volume.
What affects the speed of diffusion?
The bigger difference in the concentration of particles, the faster they diffuse
Temperature, they make particles move and spread out faster
Does pressure increase within depth?
yes
Does pressure act in all directions?
yes
Explain the properties of Pressure
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.
Why do dams have a thicker base
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
