Where does the focal point of a convex mirror fall?

In an experiment, a disk is set into motion such that it rotates with a constant angular speed. As the disk spins, a small spher

boyakko [2]

Answer:

L₀ = L_f , K_f < K₀

Explanation:

For this exercise we start as the angular momentum, with the friction force they are negligible and if we define the system as formed by the disk and the clay sphere, the forces during the collision are internal and therefore the angular momentum is conserved.

This means that the angular momentum before and after the collision changes.

Initial instant. Before the crash

L₀ = I₀ w₀

Final moment. Right after the crash

L_f = (I₀ + mr²) w

we treat the clay sphere as a point particle

how the angular momentum is conserved

L₀ = L_f

I₀ w₀ = (I₀ + mr²) w

w = $\frac{I_o}{I_o + m r^2}$ w₀

having the angular velocities we can calculate the kinetic energy

starting point. Before the crash

K₀ = ½ I₀ w₀²

final point. After the crash

K_f = ½ (I₀ + mr²) w²

sustitute

K_f = ½ (I₀ + mr²) ( $\frac{I_o}{I_o + m r^2}$ w₀)²

Kf = ½ $\frac{I_o^2}{ I_o + m r^2}$ w₀²

we look for the relationship between the kinetic energy

$\frac{K_f}{K_o}$ = $\frac{I_o}{I_o + m r^2}$

$\frac{K_f}{K_o } < 1$

K_f < K₀

we see that the kinetic energy is not constant in the process, this implies that part of the energy is transformed into potential energy during the collision

6 0

3 years ago

a heavy block is suspended from a vertical spring. the elestic potential energy is stored in the spring is 2 j. what is the spri

kati45 [8]

Answer:

k = 100 N/m

Explanation:

The elastic potential energy of a spring is equal to (1/2)kx^2, where k is the spring constant and x is the distance compressed. If the elastic PE is equal to 2J, we can solve for k. Make sure to convert units from cm to m:

(1/2)kx^2 = 2J

kx^2 = 1

k = 1/x^2

k = 1/(0.1)^2

k = 100 N/m

8 0

2 years ago

What mass of water must evaporate from the skin of a 70.0 kg man to cool his body 1.00 ∘C? The heat of vaporization of water at

romanna [79]

Answer:

100 cc

Explanation:

Heat released in cooling human body by t degree

= mass of the body x specific heat of the body x t

Substituting the data given

Heat released by the body

= 70 x 3480 x 1

= 243600 J

Mass of water to be evaporated

= 243600 / latent heat of vaporization of water

= 243600 / 2420000

= .1 kg

= 100 g

volume of water

= mass / density

= 100 / 1

100 cc

1 / 10 litres.

6 0

3 years ago

The volume of a gas can be converted to moles by

Sonja [21]

Multiplying the ideal gas law constant

7 0

3 years ago

Heellppppppppppp!!!!

alukav5142 [94]

Answer:

B, the internet serves to provide people with more insightful explanations on things that they have not experienced yet but want to find out more on.

3 0

3 years ago