Answer:
40 j, 80j.
Explanation:
P.E= mgh. G=10 m/s².
For 4m, P.E=1*10*4=40 joules.
For 8m, P.E=1*10*8=80 joules.
Answer:
2.36 x 10^6 J
Explanation:
Tc = 0°C = 273 K
TH = 22.5°C = 295.5 K
Qc = heat used to melt the ice
mass of ice, m = 85.7 Kg
Latent heat of fusion, L = 3.34 x 10^5 J/kg
Let Energy supplied is E which is equal to the work done
Qc = m x L = 85.7 x 3.34 x 10^5 = 286.24 x 10^5 J
Use the Carnot's equation


QH = 309.8 x 10^5 J
W = QH - Qc
W = (309.8 - 286.24) x 10^5
W = 23.56 x 10^5 J
W = 2.36 x 10^6 J
Thus, the energy supplied is 2.36 x 10^6 J.
The upward force the table exerts on the ground!
Equal and opposite forces.
Answer:
c = 1 / √(ε₀*μ₀)
Explanation:
The speed of the electromagnetic wave in free space is given in terms of the permeability and the permittivity of free space by
c = 1 / √(ε₀*μ₀)
where the permeability of free space (μ₀) is a physical constant used often in electromagnetism and ε₀ is the permittivity of free space (a physical constant).
Answer:
0.5m
Explanation:
v=f×lamda
v is 300m/s, f is 600Hz, lamda is ?
lamda=v/f
lamda=300/600
lamda =3/6=1/2m