Answer:
71195 seconds or 19.8 hours
Explanation:
Because the steel will be melted, beginning from room temperature, energy is needed to heat it from room temperature to 1600°C and another to melt it at 1600°C.
We take room temperature to be 27°C, the specific heat capacity of steel to be 420 J/kg/K and the specific latent heat of fusion of steel to be 440 J/kg.
The heat required to heat the steel from room temperature to 1600°C is given by
is the mass, 
is the specific heat capacity and 
is the change in temperature.
The heat required to melt it at 1600°C is
is the mass and 
is the specific latent heat of fusion of steel.
Adding both, the heat required is 
Because the oven is 65% efficient, its output power = 
Now, energy = power * time
Time = Energy/power
-- Multiply each side of the formula by 2
-- Then divide each side by t
-- Then subtract V(i) from each side.
Answer:
303.29N and 1.44m/s^2
Explanation:
Make sure to label each vector with none, mg, fk, a, FN or T
Given
Mass m = 68.0 kg
Angle θ = 15.0°
g = 9.8m/s^2
Coefficient of static friction μs = 0.50
Coefficient of kinetic friction μk =0.35
Solution
Vertically
N = mg - Fsinθ
Horizontally
Fs = F cos θ
μsN = Fcos θ
μs( mg- Fsinθ) = Fcos θ
μsmg - μsFsinθ = Fcos θ
μsmg = Fcos θ + μsFsinθ
F = μsmg/ cos θ + μs sinθ
F = 0.5×68×9.8/cos 15×0.5×sin15
F = 332.2/0.9659+0.5×0.2588
F =332.2/1.0953
F = 303.29N
Fnet = F - Fk
ma = F - μkN
a = F - μk( mg - Fsinθ)
a = 303.29 - 0.35(68.0 * 9.8- 303.29*sin15)/68.0
303.29-0.35( 666.4 - 303.29*0.2588)/68.0
303.29-0.35(666.4-78.491)/68.0
303.29-0.35(587.90)/68.0
(303.29-205.45)/68.0
97.83/68.0
a = 1.438m/s^2
a = 1.44m/s^2
Answer: The temperature and the number of molecules must reamain constant for the law to apply, and as the pressure increases, the volumen decreases proportionally.
Boyle's law states that if the temperature, T, of a given mass of gas, remains constant, the Volume, V, of the gas is in inverse relation to the pressure, p; i.e.
pV = constant (for a given mass of gas, at constant T)
Then, if p increases, V decreases proportionally to keep the relation pV = constant.
