6 - WEP2

Question 1

work done by a variable force

Answer 1

force = f(x)
WD from x2 to x1
= ∫f(x) dx from x2 to x1

Question 2

hookes law

Answer 2

force is prop to extension/compression
before the elastic limit

Question 3

tension

Answer 3

when an object is extended
T is the force in the opposite direction to the extending force

Question 4

thrust

Answer 4

when an object is compress
T is the force in the opposite direction to the compressing force

Question 5

tension/ thrust

Answer 5

λx/l

Question 6

modulus of elasticity

Answer 6

the force to double the length of the spring
before the elastic limit
low λ means its flexible and easy to extend
high λ means its stiff and difficult to extend

Question 7

WD extending a spring (EPE)

Answer 7

λx²/2l
from x2 to x1
= λ((x2)²- (x1)²)/2l

Question 8

Work done using vectors

Answer 8

WD = F.x = (|F|cosθ)(|displacement|)

Question 9

KE using vectors

Answer 9

KE = 1/2 m(v.v)

Question 10

suvat using vectors

Answer 10

v.v = u.u + 2 a.s

Question 11

power vectors

Answer 11

F.v