Lets calculate the initial speed of the block. We know that kinetic energy is given by:

Solving for v₀:

If the speed after it hits a wall is half its original speed then:
v = v₀/2 = 2 m/s / 2 = 1 m/s
Then the kinetic energy at this point is:

The inetic energy of this object at this point is 0.5 J.
Answer:
7.46 J/kg/K
Explanation:
The heat absorbed or lost is:
q = mCΔT
where m is the mass, C is the heat capacity, and ΔT is the change in temperature.
Given q = 15.0 J, m = 0.201 kg, and ΔT = 10.0 °C:
15.0 J = (0.201 kg) C (10.0 °C)
C = 7.46 J/kg/°C
Which is the same as 7.46 J/kg/K.
Answer:
I = 
we see the intensity decreases with the inverse of the distance squared
Explanation:
Intensity is defined as power per unit area,
I = P / A
in this case we have that the sound is emitted in a spherical form therefore the area is
A = 4 pi r2
therefore the intensity is
I =
as we see the intensity decreases with the inverse of the distance squared
Answer:
3600 J
Explanation:
Kinetic energy of an object is the energy posses by an object solely due to its motion.
It can also be defined as the amount of work that can be done when an moving object come to test.
Kinetic energy of an object can be calculated by the equation,
K.E. = ½mv²
Where m = mass, v = velocity
So you get,
K.E. = ½×0.5×(120)² = 3600 J
While the boy is sitting on the chair it creates a force downward on the chair and therefore the chair takes it and gives off the equal amount of force. So while he is putting force downward the chair is putting the same force upward.