Answer:
a) 2.85 kW
b) $ 432
c) $ 76.95
Explanation:
Average price of electricity = 1 $/40 MJ
Q = 20 kW
Heat energy production = 20.0 KJ/s
Coefficient of performance, K = 7
also
K=(QH)/Win
Now,
Coefficient of Performance, K = (QH)/Win = (QH)/P(in) = 20/P(in) = 7
where
P(in) is the input power
Thus,
P(in) = 20/7 = 2.85 kW
b) Cost = Energy consumed × charges
Cost = ($1/40000kWh) × (16kW × 300 × 3600s)
cost = $ 432
c) cost = (1$/40000kWh) × (2.85 kW × 200 × 3600s) = $76.95
Answer:
Mg will replace Ag in a compound
Explanation:
A single replacement reaction is driven by the position of ions on the activity series.
As a rule of thumb, the position of metal ions on the activity series determines their reactivity.
Metal ions that are above another are more reactive and they will displace those that are lower.
Generally, activity increases as we go up the group.
Mg ions are higher than Ag ions on the series so, Mg will displace Ag from a solution.
Answer:
The moment of inertia decreased by a factor of 4
Explanation:
Given;
initial angular velocity of the ice skater, ω₁ = 2.5 rev/s
final angular velocity of the ice skater, ω₂ = 10.0 rev/s
During this process we assume that angular momentum is conserved;
I₁ω₁ = I₂ω₂
Where;
I₁ is the initial moment of inertia
I₂ is the final moment of inertia
Therefore, the moment of inertia decreased by a factor of 4
The coastline/shoreline
hope this helps
Answer:
We know that potential energy of a body;
= mass(m)× gravitational acceleration(g) × height(h)
Lets find out the mass of the body
P.E. = mgh
=> 6500J = mass × 9.8m/s^2 × 12m
=>6500J = mass × ( 9.8 × 12 ) × ( m/s^2 × m)
=> 6500 Nm = m × 117.6 × m^2 / s^2
=> 6500/117.6 Ns^2/m = mass [°.° Ns^2/m = kg]
=> 55.272 Kg = mass
Therefore the mass of the body = 55.272 kg ~ <em>6</em><em>0</em><em> </em><em>k</em><em>g</em><em> </em>(Ans)
Hope it helps you
