Answer:
Explanation:
Stefan's formula for emission of radiation is
E = e σ A ( T⁴ - T₀⁴ )
E is energy radiated , e is emissivity , σ is stefan's constant , T is temperature of object and T₀ is temperature of surrounding. A is area of surface .
E = .35 x 5.67 x 10⁻⁸ ( 298⁴ - 268⁴ ) x 4π x .25²
= 1.9845 x 10⁻⁸ ( 78.86 - 51.58 ) x 10⁸ x .0625
= 3.38 J /s
Given:-
- Speed of the unicycle = 20 m/s
- Time taken = 15 s
To Find: Distance travelled by the unicycle.
We know,
s = vt
where,
- s = Distance travelled,
- v = Speed &
- t = Time taken.
Therefore,
s = (20 m/s)(15 s)
→ s = (20 m)(15)
→ s = 300 m (Ans.)
To find a general equilibrium point for a spring based on the hook law, it is possible to start from the following premise:
Hook's law is given by:

Where,
k= Spring Constant
Change in Length
F = Force
When there is a Mass we have two force acting at the System:
W= mg
Where W is the force product of the weigth. Then the force net can be defined as,

But we have a system in equilibrium, so

We find the equilibrium for any location when
