Answer:
46.19 L
Explanation:
The efficiency of the solar water heater is 40% which means 40% of the solar energy is converted to useful energy, ie. used to heat the water.
Useful energy = P = solar energy * available area * efficiency
P = 200 W/m^2 * 29.5 m^2 * 40%
P = 2360 W = 2.36 kJ/s
This means that 2.36 kJ of useful energy will be utilized per second. Converting this to the useful energy in hour gives us:
Average energy in one hour = 2.36 kJ/s * 3600 s/h = 8496 kJ
The specific heat capacity of water is 4.18 kJ/kg.C which means it will take 4.18 kJ of energy to raise the temperature of 1 kg of water by 1 degree C. Equating the energy change of the water for the given temperature rise and mass (unknown) to the useful energy utilized in one hour, we can solve to determine the unknown mass. This will give us the mass of water heated in one hour:
Energy = mass * specific heat capacity * (final temperature - initial temperature)
8496 = mass * 4.18 * (60 - 16)
mass = 46.19 kg
Lastly, this mass has to be converted to volume. Assuming density of water is constant through out the heating process:
volume = mass / density
volume = 46.19 kg / 1 kg/L
volume = 46.19 L
Answer:
a) Δp = -2.0 kgm / s, b) Δp = -4 kg m / s
Explanation:
In this exercise the change in moment of a ball is asked in two different cases
a) clay ball, in this case the ball sticks to the door and we have an inelastic collision where the final velocity of the ball is zero
Δp = p_f - p₀
Δp = 0 - m v₀
Δp = - 0.100 20
Δp = -2.0 kgm / s
b) in this case we have a bouncing ball, this is an elastic collision, as the gate is fixed it can be considered an object of infinite mass, therefore the final speed of the ball has the same modulus of the initial velocity, but address would count
v_f = - v₀
Δp = p_f -p₀
Δp = m v_f - m v₀
Δp = m (v_f -v₀)
Δp = 0.100 (-20 - 20)
Δp = -4 kg m / s
Answer:
The value 
Explanation:
From the question we are told that
The volume blood ejected is 
The velocity of the blood ejected is 
The density of blood is 
The heart beat is 
The average force exerted by the blood on the wall of the aorta is mathematically represented as
=> 
=>
<h3><u>Answer;</u></h3>
A.75°C
<h3><u>Explanation</u>;</h3>
Let the change in temp of cold water be x degrees,
while that of hot water be 100 - x degrees.
Heat exchange = mcΔt
Ice
Δt = x
m = 0.50 kg
c = 4.18 kJ/kg*°C
Hot water
Δt = 100 - x
m = 1.5 kg
c = 4.18
But;
Heat lost = heat gained
0.50 * c * x = 1.5 * c * (100 - x)
0.50 *x = 1.5*(100 - x)
0.5x = 150 - 1.5x
0.5x + 1.5x = 150 - 1.5x + 1.5x
2x = 150
x = <u>75° C</u>
Hence; the equilbrium temperature will be 75° C
