Topic 8 Flashcards
1
Q
lubricants
A
- increases effeciency
- reduces rubbing so less friction
- motion of moving parts becomes smoother
- ## noise level reduced sp less wasted useful energy
2
Q
work done
A
energy transferred by a force across a distance
3
Q
power
A
the rate at which energy is transferred
4
Q
Andrew is not injured by the fall even though he is moving quickly.
A
rate of change of momentum
Becuase andrew slowed over a long time the force was smaller
It decreased over a large disatnce
5
Q
efficency
A
mesure of how effective a task is
the ratio of outpt energy vs teh useful energy
6
Q
work done
A
upthrust in gpe
friction
stretching an elastic band
7
Q
rocket
A
is doing work ahainst its weight via thrust by transfering chemical energy into kenetic and gpe
8
Q
runner
A
is doing work
as she runs and creates a thrust towards her musles transfer chemical energy and kenetic energy
