The addition of heat energy to a
system always causes the temperature of that system to increase. This is always
true because you are adding heat of a substance to increase its temperature. For example, you are going
to drink a cup of coffee. And you wanted it hot to boost your attention. So you
have to use hot water. In order for your water to become hot or warm, you need
boil it in a kettle. Note that you are going to use an electric stove. The
electric stove gets it energy from the source giving it a hotter temperature to
the water in the kettle. You are applying heat energy to warm the water. So,
the statement is true.
Answer:

Explanation:
Deflection in the drop is due to electric field force
so we will have

acceleration of the drop is given as



now we know that time to cross the plates is given as



now the deflection is given as




Answer:
Now since mass of reactant is equal to mass of the product after the reaction so we can say that mass conservation is applicable here
Explanation:
As we know that zinc reacts with copper sulfate
so the reaction is given as

so here we have




Now total mass of reactant is given as

Mass of the product is given as

Now since mass of reactant is equal to mass of the product after the reaction so we can say that mass conservation is applicable here
Answer:
33.6 Ns backward.
Explanation:
Impulse: This can be defined as the product of force and time. The S.I unit of impulse is Ns.
From Newton's second law of motion,
Impulse = change in momentum
I = mΔv................................. Equation 1
Where I = impulse, m = mass of the skater, Δv = change in velocity = final velocity - initial velocity.
Given: m = 28 kg, t = 0.8 s, Δv = -1.2-0 = -1.2 m/s (Note: the initial velocity of the skater = 0 m/s)
Substituting into equation 1
I = 28(-1.2)
I = -33.6 Ns
Thus the impulse = 33.6 Ns backward.
(a) 
<u>Explanation:</u>
Given:
Moment of Inertia of m₁ about the axis, I₁ = m₁x²
Moment of Inertia of m₂ about the axis. I₂ = m₂ (L - x)²
Kinetic energy is rotational.
Total kinetic energy is 
Work done is change in kinetic energy.
To minimize E, differentiate wrt x and equate to zero.

Alternatively, work done is minimum when the axis passes through the center of mass.
Center of mass is at 