First law is Conservation of Energy
Second is that entropy of an isolated system will always increase with time.
Entropy is the change of disorder through time. The best statement which relates to the 2nd law is C. Thermal energy flows from areas of higher to lower temperature
Answer:
1 kg
Explanation:
The container has negligible mass and no heat is loss to the surrounding.
Mass of ice = 0.4kg, initial temperature of ice = -29oC, final temperature of the mixture = 26oC, mass of water (m2) = ?kg, initial temperature of water = 80oC, c ( specific heat capacity of water ) = 4200J/kg.K, Lf = heat of fusion of water = 3.36 × 10^5 J/kg
Using the formula:
Quantity of heat gain by ice = Quantity of heat loss by water
Quantity of heat gain by ice = mass of ice × heat of fusion of ice + mass of water × specific heat capacity of water = (0.4 × 3.36 × 10^ 5) + (0.4 × 4200 × (26- (-29) = 13.44 × 10^4 + 9.24 × 10^ 4 = 22.68 × 10^4 J
Quantity of heat loss by water = m2cΔT
Quantity of heat loss by water = m2 ×4200× (80 - 26) = m(226800)
since heat gain = heat loss
22.68 × 10^4 = 226800 m2
divide both side by 226800
226800 / 226800 = m2
m2 = 1 kg
Answer:
The speed of light (c)
Explanation:
The equation that relates the magnetic field component of an electromagnetic wave the the electric field component of the wave is:
where
E is the magnitude of the electric field component
B is the magnitude of the magnetic field component
c is the speed of light in a vacuum, whose value is
Re-arranging the equation to solve for B, we find:
Answer:
Approximately 
(assuming that the acceleration due to gravity is 
.)
Explanation:
Let 
denote the first piston's contact area with the fluid. Let 
denote the second piston's contact area with the fluid.
Similarly, let 
and 
denote the size of the force on the two pistons. Since the person is placing all her weight on the first piston:
.
Since both pistons fit into cylinders, the two contact surfaces must be circles. Keep in mind that the area of a square is equal to 
times its radius, squared:
.
.
By Pascal's Law, the pressure on the two pistons should be the same. Pressure is the size of normal force per unit area:
.
For the pressures on the two pistons to match:
.
, , and have all been found. The question is asking for . Rearrange this equation to obtain:
.
Evaluate this expression to obtain the value of , which represents the force on the piston with the larger diameter:
.
Answer:
D(t) = 8(0.83)^(t) cos 38πt
Explanation:
We are told that the spring oscillates 19 times each second.
Thus, period = 1/19
We are also told that it's pulled 8cm downwards and the amplitude decreases by 17% each second.
Thus;
Amplitude;A = 8 × (1 - (17/100))^(t)
A = 8(0.83)^(t)
If we consider the function;
y = A cos (bx - c) + d
Now, 2π/b = period
So, 1/19 = 2π/b
b = 38π
So, D(t) = 8(0.83)^(t) cos (38πt - c) + d
Since we started from minimum,
Vertical shift, d = 0 and horizontal shift c = 0
So,we now have;
D(t) = 8(0.83)^(t) cos 38πt
