Mechanics and Materials

Question 1

what are examples of scalars and vectors give 4 each

Answer 1

scalar
- mass
- temp
- distance
- speed
- energy

vector
- displacement
- velocity
- force
- acceleration
- momentum

Question 2

what’s a moment

Answer 2

it’s the turning effect of a force

Question 3

what’s a couple

Answer 3

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

Question 4

what’s the centre of mass

Answer 4

it’s the point on the object where its hole weight can act on

Question 5

how to find the centre of mass of an irregular object

Answer 5

hang the object freely from a point
then draw a vertical line downwards

hang the object from another point and draw another vertical line downwards

the centre of mass is where the two lines intersect

Question 6

what helps a car from toppling over considering its base area and centre of mass

Answer 6

for it to not topple over you need a low centre of mass and a large base area

Question 7

what are advantages of data loggers

Answer 7

data is more accurate

automatically systems have a higher sampling rate then humans

you can see data displayed in real time

Question 8

what’s hookes law and formula

Answer 8

that extension is proportional to force

F=ke

Question 9

what’s elastic and explain it

Answer 9

elastic
when’s. deformation happens the material goes back to original shape and size when forces removed

when material put into tension, the atoms of the material are pulled apart from one another.

and atoms can move small distances relative to their equilibrium positions without acc changing position in the material

once the load is removed, the atoms return to their equilibrium distance apart

Question 10

what’s plastic and explain it

Answer 10

when a deformation happens its permanently stretched

• the atoms in the material move position relative to one another

when load is removed the atoms don’t return to original positions

an abject stretched past its elastic limit shows plastic deformation

Question 11

what’s always conserved when stretching

Answer 11

energy

Question 12

what are the two types of forces in young modulus

Answer 12

tensile — +ve

compressive — -ve

Question 13

why do engineers use young modulus

Answer 13

its for stiffness of material

so they use it to make sure materials they are using can withstand sufficient forces