Answer:
A
Explanation:
There is a mechanical advantage in this system....
she only needed 100 N to lift 500 N
1:5 she lifted it 2 meters, so if there WAS NO friction, she would have to pull in 5 x 2 = 10 meters
but there IS friction so she must have pulled in MORE than 10 m
Answer:
180 kJ
Explanation:
Given that:
Mass (m) = 5 kg
Initial temperature (T1) = 28°C
Final temperature (T2) = 68°C
The change in temperature (ΔT) = T2 - T1 = 68°C - 28°C = 40°C
Specific heat capacity of aluminium (c) = 900 J/kg°C
The quantity of heat energy required (q) is given by:
q = mcΔT
q = 5 kg × 900 J/kg°C × 40°C
q = 180000 Joules
q = 180 kJ
Therefore 180 kJ is required to raise the temperature of aluminium from 28°C to 68°C.
My workout schedule is day on - day off
This helps the body rest after the work out and let it gain/build muscle mass
Good luck
Answer:
0.237 (23.7 %)
Explanation:
The thermal efficiency of an engine is given by:
where
W is the useful work output of the engine
is the heat in input
Here we have:
and the work done is the total heat in input minus the heat exhausted:
So, the efficiency is
(23.7 %)
