Physics P2.1 Forces and their effects

• Created by: shcoool
• Created on: 24-05-15 19:48
When two objects interact...
... the forces they exert on each other are equal and opposite
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What is the resultant force?
The combined effect of the forces acting on an object
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What may a resultant force do?
It may cause a change in its state of rest or motion
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If the resultant force is zero...
... on a stationary object, it will remain stationery/ on a moving object, it will continue to move at the same speed and in the same direction
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If the resultant force is not zero...
... on a stationary object, it will accelerate in the direction of the resultant force
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What determines the acceleration of an object?
the resultant force acting on the object and the mass of the object F=ma
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On a distance-time graph how do you measure the speed?
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How do you calculate the acceleration?
v-u/t
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On a velocity-time graph, how do you calculate the acceleration?
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What are the forces like when a vehicle travels at a steady speed?
the resistive forces balance the driving force
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The greater the speed of a vehicle...
... the greater the braking force needed to stop it in a certain distance
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What is the stopping distance?
The sum of the distance the vehicle travels during the driver's reaction time (thinking time) and the distance it travels under the braking force (braking distance)
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What can the driver's reaction time be affected by?
Tiredness, drugs and alcohol
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What happens when the brakes of a vehicle are applied?
Work done by the friction force between the brakes and the wheel reduces the kinetic energy of the vehicle and the temperature of the brakes increase
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What can a vehicle's braking distance be affected by?
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The faster an object moves through a fluid...
... the greater the frictional force acting on it
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What happens to an object falling through a fluid?
It will initially accelerate due to the force of gravity and eventually the resultant force will be zero and the object will move at its terminal velocity
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How do you calculate the weight of an object using the force exerted on it by a gravitational force?
W = m*g
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What may a force acting on an object affect the shape?
It may cause a change in shape of the object
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What may a force applied to an elastic object do?
It will result in the object stretching and storing elastic potential energy
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What should happen for an object to recover its original shape?
Elastic potential energy is stored in the object when work is done on the object to change its shape
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The extension of an elastic object is...
... directly proportional to the force applied, provided that the limit of proportionality is not exceeded: F = k*e
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Other cards in this set

Card 2

Front

What is the resultant force?

Back

The combined effect of the forces acting on an object

Card 3

Front

What may a resultant force do?

Card 4

Front

If the resultant force is zero...

Card 5

Front

If the resultant force is not zero...