Answer:
Explanation:
Mass of nails is 0.25kg
Mass of hammer 5.2kg
Speed of hammer is =52m/s
Then, Ben kinetic energy is given as
K.E= ½mv²
K.E= ½×5.2×52²
K.E= 7030.4J
Given that, two-fifth of kinetic energy is converted to internal energy
Internal energy (I.E) = 2/5 × K.E
Internal energy (I.E) = 2/5 × 7030.4
I.E=2812.16J.
Energy increase is total Kinetic energy - the internal energy
∆Et= K.E-I.E
∆Et= 7030.4 - 2812.16
∆Et= 4218.24J
Weight of the carriage 
Normal force 
Frictional force 
Acceleration 
Explanation:
We have to look into the FBD of the carriage.
Horizontal forces and Vertical forces separately.
To calculate Weight we know that both the mass of the baby and the carriage will be added.
- So Weight(W)

To calculate normal force we have to look upon the vertical component of forces, as Normal force is acting vertically.We have weight which is a downward force along with
, force of
acting vertically downward.Both are downward and Normal is upward so Normal force 
- Normal force (N)

- Frictional force (f)

To calculate acceleration we will use Newtons second law.
That is Force is product of mass and acceleration.
We can see in the diagram that
and
component of forces.
So Fnet = Fy(Horizontal) - f(friction) 
- Acceleration (a) =

So we have the weight of the carriage, normal force,frictional force and acceleration.
Energy and Work have the same unit of measurement which is Joules in SI units.
Explanation:
- A Joule of Work is said to be done on an object when energy is transferred to that particular object.
- If two objects are involved, when one object transfers energy onto the second, a joule of work is said to be done by the first object.
- Work is also the application of force on an object over a distance. So Work = Force × Displacement
- Energy is neither created nor destroyed. It is in 2 forms - kinetic and potential.
- Kinetic energy is defined as the energy of a moving object while potential energy is known as the energy that is stored within an object.
- Kinetic Energy = 1/2 × mass × (velocity)²
- Potential Energy = mass × acceleration due to gravity × height
- Both energy and work are measured in Joules.
Considering the unknown resistence as R and using the Ohm's First Law, we have:
The equivalent resistence is given by the resistor series with the lamp resistence.

If you notice any mistake in my english, please let me know, because i am not native.