Answer:
(a) 
(b) 
Explanation:
(a) Since a constant external force is applied to the body, it is under an uniformly accelerated motion. Using the following kinematic equation, we calculate the final velocity of the mass if it is initially at rest(
):

According to Newton's second law:

Replacing (2) in (1):

(b) In this case we have
. So, we use the final velocity equation:

Answer: The increase in temperature of the nail after the three blows is 8.0636 Kelvins. The correct option is (d).
Explanation:
Kinetic energy of the hammer ,K.E.=

Half of the kinetic energy of the hammer is transformed into heat in the nail.
Energy transferred to the nail in one blow =

Total energy transferred after 3 blows,Q =
Mass of the nail = 15 g = 0.015 kg
Change in temperature =
Specif heat of the steel = c = 448 J/kg K



The increase in temperature of the nail after the three blows is 8.1 Kelvins.Hence, correct option is (d).
Strength of induced current increased when strength of magnetic field increases. It will also increase when the number of turns are increased or if the speed of conductor increases
Answer:
A) atmospheric pollutants. Nuclear power plants do not produce air pollution as carbon dioxide, sulfur dioxide.
Hope this helps!