Answer:
.
Explanation:
Let
denote the absolute temperature of this object.
Calculate the value of
before and after heating:
.
.
By the Stefan-Boltzmann Law, the energy that this object emits (over all frequencies) would be proportional to
.
Ratio between the absolute temperature of this object before and after heating:
.
Therefore, by the Stefan-Boltzmann Law, the ratio between the energy that this object emits before and after heating would be:
.
Answer:
40 N
Explanation:
We are given that
Speed of system is constant
Therefore, acceleration=a=0
Tension applied on block B=T=50 N
Friction force=f=10 N
We have to find the friction force acting on block A.
Let T' be the tension in string connecting block A and block B and friction force on block A be f'.
For Block B

Where
=Mass of block B
Substitute the values


For block A

Where
Mass of block A
Substitute the values


Hence, the friction force acting on block A=40 N
<h2>Answer </h2>
<h3>1) iron </h3>
<h3>2) Aluminium </h3>
<h3>3) sliver </h3>
<h3>4) copper </h3>
I hope it's helpful for you ☺️
I think it is B as 168/20