how much work www does the motor do on the platform during this process? enter your answer in joules to four significant figures
1 answer:
You might be interested in
Answer:
(a)
(b) P = 0.816 Watt
Explanation:
(a)
The power radiated from a black body is given by Stefan Boltzman Law:
where,
P = Energy Radiated per Second = ?
σ = stefan boltzman constant = 5.67 x 10⁻⁸ W/m².K⁴
T = Absolute Temperature
So the ratio of power at 250 K to the power at 2000 K is given as:
(b)
Now, for 90% radiator blackbody at 2000 K:
<u>P = 0.816 Watt</u>
Answer:
48.16 %
Explanation:
coefficient of restitution = 0.72
let the incoming speed be = u
let the outgoing speed be = v
kinetic energy = 0.5 x mass x
- incoming kinetic energy = 0.5 x m x
- coefficient of restitution =
0.72 =
v = 0.72u
therefore the outgoing kinetic energy = 0.5 x m x
outgoing kinetic energy = 0.5 x m x
outgoing kinetic energy = 0.5184 (0.5 x m x )
recall that 0.5 x m x is our incoming kinetic energy, therefore
outgoing kinetic energy = 0.5184 x (incoming kinetic energy)
from the above we can see that the outgoing kinetic energy is 51.84 % of the incoming kinetic energy.
The energy lost would be 100 - 51.84 = 48.16 %