work, power and energy

Question 1

work

Answer 1

when a force acts on a body, 
work done by the force is equal to
magnitude x distance the body moves
W = Fd
(N)(m)

Question 2

joule

Answer 2

N.m

Question 3

positive work

negative

Answer 3

force in the same direction, body moves

opposite

Question 4

concentric

muscular work

Answer 4

positive work

W = tensile force x distance the muscles stretches

Question 5

power

Answer 5

rate at which at work is performed

P(ower developed) = W/t

Question 6

watts

Answer 6

N.m/s

1 horsepower = 746 watts

Question 7

energy

Answer 7

capacity to do work

Question 8

mechanical

theres 3 types

Answer 8

kinetic
potential
strain

Question 9

kinetic

Answer 9

energy bc of its motion
KE = 1/2 x mass x (velocity)squared

is used to deform an object to create strain energy + heat

Question 10

potential energy

Answer 10

position in relation to earths surface
stored energy
gravitational energy
PE = weight x height above surface

Question 11

strain energy

Answer 11

capaicty to do work while if reforms after being deformed
elastic potential energy
stored energy
SE = 1/2 x k(a spring constant) x x(distance over which the material is deformed)

Question 12

law of conservation of mechanical energy

Answer 12

is constant when gravity is the only external force

PE + KE + SE = C

Question 13

work

Answer 13

= change in KE + change in PE + change TE