Physics-force And Motion Flashcards
True or false
Can more than one force act on an object
True
When forces of an object are balance the object must be
Stationary or travelling at a steady speed
Wh do people reach terminal velocity
The faster the person if falling he greater the air resistance
What is a useful way to represent the motion of an object
A distance-time graph
Forces can cause objects to turn on a pivot what is this called
Moments
If the moment is balanced what must be equal
The anti-clockwise moment and the clockwise moment
What is the equation for a moment
Moment = force (N) x distance (m or cm)
What is the equation for speed
Speed= distance/time
When do elastic materials change shape
When a force is exerted on them
When does compression happen
Compression happens when a material or object is squashed
When an elastic material changes shape by being stretched or squashed what is is called
Deformation
True or false
The greater amount of force exerted the less amount of deformation
False
The greater the force exerted the greater the amount of deformation
Hookes law says that the extension of an elastic object is directly proportional to tho the force applied, so if the force applied is doubled then does the extension double
Yes
What is the word equation for pressure
Pressure = force/area
Why do sink into snow when you walk in it
Your shoes are too small a surface area to spread uo your weight so you sink into the snow because the pressure on the snow is too high
What angle to liquids exert pressure on surfaces
90degrees
What does the atmosphere exert reassure on
The atmosphere exerts pressure on you and everything around you
How does atmospheric pressure changes with altitude, so what happens when you go higher
The weight of air above you is lower
There is lower atmospheric pressure
The pressure in liquids changes with dept, so the deeper you go what happens
The greater the weight of liquid above
The greater the liquid pressure
Why does an object float
If the object has a lower density than at of the surrounding liquid or gas it will float
