Ch. 6 Scalar and vector

Question 1

what’s a scalar and vector

Answer 1

a scalar has no direction it’s just the amount of smth

ex. mass, temp, time, speed

a vector has magnitude and direction

ex. displacement, velocity, force, acceleration

Question 2

what’s a moment and what’s formula

Answer 2

a turning effect of a force

M=Fd

force x perpendicular distance from the point to the line of action of force

Question 3

what is equilibrium

Answer 3

the sun of the clockwise moments bout any point equals the sum of the anti-clockwise moments about the same point

Question 4

what’s a couple

Answer 4

a pair of forces of equal size which act parallel to each other but in opposite directions

it doesn’t produce a turning effect

Question 5

what does inertia mean

Answer 5

any mass has a resistance to a change in velocity when subjected to a force

Question 6

what is centre of mass

Answer 6

it’s the single point that you can consider it’s whole weight to act through

Question 7

how do you get the centre of mass of an irregular object

Answer 7

1. hang the object freely from a point
2. draw vertical line downwards from the point of suspension
3. hang the object from a diff point
4. draw anotherr vertical line downwards
5. center of mass is where the two lines cross

Question 8

how does an object topple over

Answer 8

if the vertical line drawn downwards from its centre of mass falls outside its base area

this happens because of a resultant moment occurs which causes a turning effect

the lower the centre of mass and the bigger the base area, the more stable the object is