# Physics P2

• Created by: Amy_5639
• Created on: 16-04-18 08:30
1.What is the difference between a scalar and a vector quantity?
Scalar=only numbers e.g.speed, distance, time, mass etc Vector=direction as well e.g.velocity, displacement, force, acceleration etc
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2.Define acceleration in terms of velocity.
Acceleration is how quickly the velocity is changing.
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3.Explain why an object travelling in a circle at a constant speed is accelerating.
Because it has a changing velocity as it's always travelling in different directions so it's always accelerating
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4.Describe an experiment to investigate the acceleration of a trolley down a ramp.
1.Set up ramp on runway,put trolley at top of ramp+3 light gates,1 at front of trolley on ramp,2 at end of ramp,3 at end of runway.2.Measure distance between light gates then let trolley go down ramp.3.Between gates: 1+2 average speed, 2+3 speed on
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5.How is the speed of an object found from a distance-time graph?
The speed equals the gradient, so find the gradient of the graph by doing change in vertical (divided by) change in horizontal. If graph is curved draw a tangent then work out the gradient of the tangent
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6.What does a flat section on a velocity-time graph represent?
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7.How is the distance travelled by an object found from its velocity-time graph?
You can estimate the distance travelled from the area under a graph by counting squares. Find the distance that 1 square represents then multiply width and height of square, and multiply it by the number of squares under the graph
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8.What is meant by the 'resultant force' acting on an object?
It's the overall force on a point or object
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9.What will happen to an object that has a zero resultant force?
The object will either be stationary or moving at a steady speed
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10.What will happen to an object that has a non-zero resultant force?
The object will either accelerate or decelerate
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11.What is Newton's First Law of Motion?
It says that:"an object will remain stationary or at a constant velocity unless acted upon by an external force. So no resultant force means no change in velocity
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Give the equation for Newton's Second Law.
Force (N) = Mass (kg) x Acceleration (m/s squared) or F=ma
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13.Explain how a car moving with a constant driving force will reach terminal velocity.
When car sets off there's more driving force than friction force so they accelerate.But resistance is directly proportional to velocity so as velocity increases, resistance does too.This reduces the acceleration until friction force= driving force.
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14.What is inertia?
The measure of how difficult it is to change an objects velocity
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15.What is Newton's Third Law of Motion? Give an example of it in action
It says:"when two objects interact they forces they exert on each other are equal and opposite- so reaction forces are equal and opposite. E.g. if you push a trolley the trolley will push back against you just as hard
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16.Give the equation for momentum in terms of mass and velocity.
Momentum (kg m/s) = mass (kg) x velocity (m/s) or p=m x v
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17.What is an elastic collision?
It's where total energy in the kinetic energy stores of the objects colliding is the same before and after the collision-i.e. energy in the kinetic store is conserved
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18.What is the difference between mass and weight and how can weight be calculated?
Mass is the actual amount of material contained in a body, whereas weight is the force exerted by the gravity on that object. Mass in independent but wight is different on Earth, Moon etc. Weight(N)=mass(kg) x gravitational field strength(N/kg)
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19.Give the equation for the energy in an objects gravitational potential energy store.
Potential energy(J)=mass(kg) x height(m) x gravitational field strength(N/kg) or PE=m x h x g
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20.Give the equation for the energy in the kinetic energy store of a moving object.
Kinetic energy(J)= 0.5 x mass(kg) x (speed)squared (m/s squared) or KE= 0.5 x m x v squared
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21.Give the equation for the work done on an object when it's moved a certain distance by a force.
Work done(J)= force(N) x distance(m) or W=F X d
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22.What is meant by power? How is power calculated?
Power is the rate at which energy is transferred. Power(W)= workdone(J) (divided by) time(s) or P=W (divided by) t
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23.What is the minimum number of forces needed to stretch, compress or bend an object?
2
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24.Give the equation that is known as the Hooke's law.
Force exerted by a spring(N)= extension(m) x spring constant(N/m)
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25.What constant can be found from calculating the gradient of a force-extension graph for a material obeying Hooke's law?
The gradient of the straight line is equal to the spring constant of the object- the larger the spring constant, the steeper the gradient
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26.What is the difference between an elastic deformation and a plastic deformation?
If an object returns to its original shape after the forces are removed it's an elastic deformation. If the object doesn't return to its original shape when you remove the forces it's a plastic deformation
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27.Describe a simple experiment to investigate Hooke's law.
Hang spring from clamp stand, without masses, then measure springs original length.Weigh masses and add on one at a time to the hook.After each mass added measure new length of spring. Plot graph of force against extension using results
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28.Give the equation for calculating the energy transferred to a spring when it's stretched.
Energy transferred in stretching(J)= 0.5 x spring constant(N/m) x (extension) squared (m squared) or E = 0.5 x k x (x)squared
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## Other cards in this set

### Card 2

#### Front

2.Define acceleration in terms of velocity.

#### Back

Acceleration is how quickly the velocity is changing.

### Card 3

#### Front

3.Explain why an object travelling in a circle at a constant speed is accelerating.

### Card 4

#### Front

4.Describe an experiment to investigate the acceleration of a trolley down a ramp.

### Card 5

#### Front

5.How is the speed of an object found from a distance-time graph?