Answer:
Explanation:
The rate at which heat will be radiated is given by the expression
E = e Aσ ( T⁴ - T₀⁴ )
E is heat radiated , e is emissivity , A is area of surface , σ is stephan's constant T is temperature of the object and T₀ is temperature of the surrounding .
For all the objects given , e , σ T and T₀ are same so E will solely dependent on area of the surface
surface area of cube= 6 r² ,
surface area of sphere = 4 π r²
= 12.56 r²
hemisphere = 2 π r²
= 6.28 r²
12.56 r² >6.28 r² > 6 r²
heat radiated by sphere > heat radiated by hemisphere > heat radiated by cube .
Answer:
a. Her moment of inertia increases and she rotates slower.
Explanation:
As we know that initially when she starts her motion she is in piked position due to which her whole mass is concentrated near the axis of rotation
So here the rotational Inertia of her body will be smaller
Now when is comes closer to the position of landing she extends into layout position due to which her mass will move away from the axis of rotation
Due to this the rotational inertia of her body will increase
now we know that there is no external torque on the system
so here angular momentum must be conserved
So we will have
so if rotational inertia is increasing then angular speed must be slower
so correct answer will be
a. Her moment of inertia increases and she rotates slower.
Answer:
Density of body = 0.25g/cc
Explanation:
Given:
Volume submerged in water = 3/4
Find:
Density Of Body
Computation:
Density of body = fraction of body in liquid x density of water
Density of body = [1-3/4]1
Density of body = 0.25g/cc
Ummmmmmmmmm is this what subject??????? Because I hv no idea unless u tell me a subject
The correct answer is Option C) Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.
As the coefficient of absorption would define the energy present in the reflected wave, the material C has the highest percentage of absorption i.e. 62% and would be best suitable to make a sound proof room.
