Forces And Motion Vocab

Question 0

Weight

Answer 0

The pull of gravity on an object which has mass - a force
Depends on: -mass of an object
-the size of the gravitational field (which planet you are on)
Newtons (N)
Force on an object that has mass, due to gravitational attraction
W=mg (g=gravitational field strength)

Question 1

Mass

Answer 1

Measures the resistance of an object to accelerate (changes in motion)
The amount of matter in an object
Never changes
In Kilograms

Question 2

Displacement

Answer 2

Distance moved from original point

Question 3

Centre of mass/gravity

Answer 3

The point through which the whole weight of the object seems to act

Question 4

Equilibrium

Answer 4

Clockwise = anticlockwise
No resultant force/motion
Balanced
Force downwards = force upwards
Total moment = 0
Centre of mass directly above/below pivot

Question 5

Stable object

Answer 5

Doesn’t topple over easily if acted upon by a force
Returns to equilibrium position when force removed
Depends on centre of mass
More stable with larger base and lower centre of mass

Question 6

Force

Answer 6

A push or pull
Vectors
Newtons (N)

Question 7

Vector

Answer 7

Both magnitude and direction

Question 8

Reaction (force)

Answer 8

Force on an object resting on a surface that acts perpendicular to that surface

Question 9

Tension (force)

Answer 9

Force on a stretched object

Question 10

Lift (force)

Answer 10

Upward force on the wing of an aeroplane

Question 11

Friction

Answer 11

Contact force that opposes the motion of one object sliding over another

Question 12

Air resistance

Answer 12

Frictional force opposing the motion of an object through a fluid

Question 13

Thrust

Answer 13

Push due to a rocket engine

Question 14

Up thrust

Answer 14

Buoyancy force acting upwards on an object immersed in a fluid

Question 15

Resultant force

Answer 15

Overall force with all forces combined (take smaller one away from the larger)

Question 16

Inertia

Answer 16

Tells how much an object accelerates relating to it’s mass eg. heavier=harder to move

Question 17

Velocity

Answer 17

Speed and direction of object described
Vector quantity eg. displacement, force
Direction as well as magnitude

Question 18

Speed

Answer 18

=magnitude of the velocity

Scalar quantity

Question 19

Terminal velocity

Answer 19

The fastest a falling object can travel at
Resultant force=0
Balanced forces
No longer accelerates - constant speed
Depends on surface area+weight of object
Air resistance=weight

Question 20

Free fall

Answer 20

An object falling without air resistance under the earths gravitational field
Depends on: size, shape and surface area of object

Question 21

Acceleration

Answer 21

Rate of change in velocity

A=Δv/t

Question 22

Moment

Answer 22

Turning effect about a pivot
Eg. Opening a door, wheelbarrow etc.
moment=force x perpendicular distance to the pivot