P8: Forces In Balance

Question 1

What does scalar mean?

Answer 1

Scalar quantities have only magnitude (size).

Question 2

What does vector mean?

Answer 2

A vector quantity contains both direction and magnitude.

Question 3

Give an example of a vector.

Answer 3

Velocity
Force
Displacement (m)
Momentum (kgm/s)

Question 4

Give an example of a scalar.

Answer 4

Speed
Time
Distance
Mass

Question 5

A force is an operation that causes an object to:

Answer 5

Change direction
Change force
Change speed

Question 6

What are the five contact forces?

Answer 6

Frictional
Tension
Reaction
Air
Spring

Question 7

What are the 3 non-contact forces?

Answer 7

Magnetic
Electrical
Gravitational

Question 8

What is force measured in?

Answer 8

Newtons

Question 9

Is gravity a force?

Answer 9

No

Question 10

If the resultant force on an object is 0…

Answer 10

The object is either stationary or moving at a constant speed.

Question 11

What is mass?

Answer 11

A measurement of all the matter (stuff) an object is made up of.

Question 12

What is weight?

Answer 12

The force an object has on another body

Question 13

What is mass measured in?

Answer 13

Kg or g

Question 14

What is weight measured in?

Answer 14

Newtons

Question 15

What is the equation linking weight and mass?

Answer 15

Wright = mass x gravitational field strength

Question 16

What is gravitational field strength measured in?

Answer 16

N/Kg or m/s ^2

Question 17

When do balanced forces occur?

Answer 17

When more than one force acts on an object and they are equal in size and opposite in direction.

Question 18

Unbalanced forces acting on an object will cause _____.

Answer 18

Acceleration

Question 19

What is a resultant vector?

Answer 19

The vector that results from the addition of two or more vectors in a vector sum.

Question 20

What is the law of moments?

Answer 20

For an object to be in equilibrium (balance), the clockwise moments must be equal to the anti-clockwise moments.

Question 21

What is the equation for moments?

Answer 21

M=Fxd

Question 22

What is the units for moments?

Answer 22

Nm

Question 23

What is the centre of mass of an object?

Answer 23

The point at which its mass can be thought of as being concentrated.

Question 24

What is suspended equilibrium?

Answer 24

when the centre of mass is directly below the point where it is suspended.

Question 25

Why are gears used?

Answer 25

Is are used to increase the turning affect (moment), they do this by increasing the distance to the pivot (same as radius of the gear).