Flashcards
p3-b - 2
Flashcards do conjunto (8)
- 1What happens when you try to squeeze a liquid ?Liquids are virtually incompressible, and the pressure in a liquid is transmitted equally in all directions
- 2Describe the principle o a hydraulic systema hydraulic system uses the pressure in a fluid to exert a force
The use of different cross-sectional areas on the effort and load side of a hydraulic system enables the system to be used as a force multiplier.
a small effort can be used to move a large load - 3the force exerted by a hydraulic pressure system depends on what ?1. the force exerted on the system
2. the area of the cylinder on which this force acts on
3. the area of the cylinder that exerts the force - 4state the units used in the below equationP is the pressure in pascals, Pa
F is the force in newtons, N
A is the cross-sectional area in metres squared, m - 5describe circular motionWhen an object moves in a circle it continuously accelerates towards the centre of the circle. This acceleration changes the direction of motion of the body, not its speed.
- 6what is centripetal force ?The resultant force causing this acceleration is called the centripetal force and is always directed towards the centre of the circle.
- 7state 3 things that increase centripetal force ?The centripetal force needed to make an object perform circular motion increases as:
■ the mass of the object increases
■ the speed of the object increases
■ the radius of the circle decreases. - 8State examples of forces that result in centripetal force1. a conker on a piece of string around in a circle. The centripetal force is the result of tension within the string.
2. For a vehicle turning a corner, the centripetal force is provided by friction between the tyres and the tarmac
3. For objects in orbit, for example the Earth orbiting the Sun, the centripetal force is provided by gravity