Answer:
3.) 463 J/g
Explanation:
Heat given by the fuel is used to increase the temperature of the water
so it is given as

here we will have
m = 250 g

now we also know that

so we have


so 3.5 g fuel gives above energy
so per gram of fuel will have total energy given as


Answer:
The stress is calculated as 
Solution:
As per the question:
Length of the wire, l = 75.2 cm = 0.752 m
Diameter of the circular cross-section, d = 0.560 mm = 
Mass of the weight attached, m = 25.2 kg
Elongation in the wire, 
Now,
The stress in the wire is given by:
(1)
Now,
Force is due to the weight of the attached weight:
F = mg = 
Cross sectional Area, A = 
Using these values in eqn (1):
Speed= distance/ time so distance = speed * time= 28 * 20= 560m .. so the answer is 560m.. l hope it helped :)
Answer: R=24.2Ω
Explanation: <u>Power</u> is rate of work being done in an electric circuit. It relates to voltage, current and resistance through the following formulas:
P=V.i
P=R.i²

The resistance of the system is:



R = 24.2Ω
<u>For the device, resistance is 24.2Ω.</u>