Mass of the object m = 25 kg
Coefficient of friction Uk = 0.15
Frictional force Ff = Uk x F => Ff = Uk x m x g
Ff = 0.15 x 25 x 9.8
Frictional Force Ff = 36.75 N
The total power emitted by an object via radiation is:

where:
A is the surface of the object (in our problem,


is the emissivity of the object (in our problem,

)

is the Stefan-Boltzmann constant
T is the absolute temperature of the object, which in our case is

Substituting these values, we find the power emitted by radiation:

So, the correct answer is D.
Time = (distance) / (speed)
= (30 km) / (30 m/s)
= (30,000 m) / (30 m/s)
= (30,000 / 30) sec
= 1,000 seconds
= 16 minutes 40 seconds
It is a completely false statement that in <span>any energy transformation, there is always some energy that gets wasted as non-useful heat. The correct option among the two options that are given in the question is the second option. I hope that this is the answer that has actually come to your desired help.</span>
Answer:
Why is gravity so weird? No force is more familiar than gravity — it's what keeps our feet on the ground, after all. And Einstein's theory of general relativity gives a mathematical formulation for gravity, describing it as a “warping” of space.