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Flashcards in P3 Deck (20):
1

Proportional

If 2 variables are proportional then if one is doubled so is the other. If proportional variables are plotted on a graph then they will lie in a straight line with a positive/negative gradient which passes through the origin

2

Line of best fit

It is drawn through real experimental data plotted on a graph and allows for a few anomalies due to inaccuracies in collecting the data. The line is drawn with a rule on the graph and it best represents the trend of points.

3

Gradient

The slope of the graph. It is usually measured as the change in y (rise)/the change in x (run).

4

Spring constant

a measure of the stiffness of the spring. It is measure in N/m or N/cm

5

Spring constant equation

k=F/x. Spring constant= force/extension

6

Force

a push, pull or twist applied to an object. It is measured in Newtons.

7

Weight

the force of graviy acting on an object measured in Newtons, defined as W=mg where m is the mass of an object in kg and g is acceleration due to gravity in m/s/s or N'kg. On Earth, g=10N/kg

8

Normal contact force

the upward push of the ground on an object measured in Newtons. It usually acts at 90 degrees to the surface and often is equal to the weight of the object but opposite in direction.

9

Balanced forces

If all forces acting on an object cancel each other out so that the resultant/ total force is 0.

10

Unbalanced forces

If the forces acting on an object have a resultant force when added up. An unbalanced force may cause an object to accelerate, change direction or both.

11

Equilibrium

If all forces acting on an object are balanced. This means that the object will continue to move at a constant velocity. A stationary object (velocity=om/s) is also at an equilibrium

12

Friction

a resistance force which opposes the motion of an object, caused when 2 surfaces rub against each other

13

Air resistance

a resistive force which opposes the motion of an object, caused when an object moves through air. The air molecules collide with the object and oppose the motion

14

Free body diagram

A diagram which illustrates all the forces acting on an object. The object is usually represented by a point or a small box. The forces are drawn on the object as arrows and are shown acting in the correct direction. The larger the arrow, the bigger the force

15

Newton's first law

If the forces acting on an object are balanced, the object remains in equilibirum i.e it will continue to move at a constant velocity (which may be at 0)

16

Newton's second law

If an unbalanced force, F, acts on an object then the acceleration of the object, a, may be calculated using F=ma where m is the mass in kg

17

Extension of the spring

shows how much its length has increased from its original length. Extension= Stretched length-original (unloaded) length

18

Elastic

An elastic material changes shape when an external force is applied but returns to its original shape when the force is removed

19

Extension

The extension of a spring is the difference between the stretched length and the natural length

20

Hooke's law

Force applied is proportional to the extension, or F=kx