Write the fallowing in scientific notation 1020?

A system of two objects has ΔKtot = 6 J and ΔUint = -5 J. Part A How much work is done by interaction forces? Express your answe

Elina [12.6K]

A) +5 J

B) +1 J

Explanation:

A)

The internal forces (interaction forces) acting on a system do not change the mechanical energy (sum of potential and kinetic energy) of the system.

However, these forces are responsible for converting the energy from one form into another; the work done by these forces is equal to the amount of energy converted from one form into the other.

In this problem, we have:

$\Delta U=-5 J$ is the loss in potential energy of the system

$\Delta K=+6 J$ is the gain in kinetic energy of the system

By looking at these numbers, this means that the internal forces have converted 5 J of energy from potential energy into kinetic energy (while the additional +1 J missing is due to external forces, as explained in part B).

Therefore, the work done by internal forces is

W = +5 J

B)

First of all, we calculate the change in mechanical energy of the system.

The mechanical energy of a system is the sum of its kinetic energy (K) and its potential energy (U):

$E=K+U$

So, the change in mechanical energy is equal to the sum of the changes of kinetic energy and the changes of potential energy:

$\Delta E= \Delta K + \Delta U$

In this problem:

$\Delta K=+6 J$

$\Delta U=-5 J$

So, the change in mechanical energy is:

$\Delta E=+6+(-5)=+1 J$

According to the work-energy theorem, the work done by external forces on a system is equal to the change in mechanical energy of the system: therefore in this case, the work done by external forces is

$W=\Delta E=+1 J$

5 0

4 years ago

The amount of electric energy consumed by a 60 watt lightbulb for 1 minute could lift a 10 newton object to a maximum vertical h

Angelina_Jolie [31]

Answer: physics are fake

Explanation:

8 0

2 years ago

The reciprocal of frequency is

Colt1911 [192]

Frequency=1/T, where T is the time period.
Reciprocal of frequency = T or it can be written as T = 1/f, where f is frequency.

8 0

3 years ago

Determine the number of ways the faces of a regular tetrahedron can be colored with three colors

GREYUIT [131]

Tetrahedron is a geometrical figure or solid that is formed in similar manner as a pyramid. The faces of the formed pyramid are triangles. Also is the base.

By the statement above, it can be deduced that the figure has four sides. The number of ways in which the sides can be colored by any of the three (3) colors is,
3 x 3 x 3 x 3 = 81

Since the sides can still have the same colors, we deduct this value by 3 in order to eliminate the uniform colors of the four sides.
= 81 - 3 = 78

Also, we can eliminate the concern on only two colors can mix,
= 3 x 2 = 6
Subtracting,
78 - 6 = 72

Hence, the answer is 72.

5 0

3 years ago

What is Snell's Law?

polet [3.4K]

Answer:

law stating that the ratio of the sines of the angles of incidence and refraction of a wave are constant when it passes between two given media.

Snell's law, in optics, a relationship between the path taken by a ray of light in crossing the boundary or surface of separation between two contacting substances and the refractive index of each. ... Snell's law asserts that n1/n2 = sin α2/sin α1.

3 0

3 years ago