If we know the total energy in a system is 30 J, and we know the PE is 20 J. What is the KE?

Describe the energy transformation in a flashlight

anastassius [24]

Answer: When the flashlight is turned on, the chemical energy stored in batteries is converted into electrical energy that flows through wires of flashlight. This electrical energy is then transformed into light and heat energies.

Explanation:

4 0

3 years ago

HELP ASAP! GIVING BRAINLIEST!!!<br><br> I need the answers to 1,2,3!!

artcher [175]

1) 72/4 = 18 years

2) 72/10 = 7.2 years

3) 72/13 = 5.54 years

Explanation: With the rule of 72, you simply take 72 and divide it by whatever the rate of return (or return on investment) is.

Let me know if you have any questions.

7 0

3 years ago

An object is pushed with a force of 400 N for 20 meters; what is the work done on the object? Solve using W=F*d

nika2105 [10]

Answer:

W = Fd = 400(20) = 8000 J

Explanation:

5 0

3 years ago

The Sun’s surface temperature is about 5800 K and its spectrum peaks at 5000 Å. An O-type star’s surface temperature may be 40,0

nirvana33 [79]

(a) $7.25\cdot 10^{-8}m$

Wien's displacement law is summarized by the equation

$\lambda = \frac{b}{T}$

where

$\lambda$ is the peak wavelength

$b=2.898\cdot 10^{-3} m \cdot K$ is Wien's displacement constant

T is the absolute temperature at the surface of the star

For an O-type star, we have

T = 40,000 K

Therefore, its peak wavelength is

$\lambda = \frac{2.898\cdot 10^{-3}}{40000}=7.25\cdot 10^{-8}m$

(b) Ultraviolet

We can answer this part by looking at the wavelength range of the different parts of the electromagnetic spectrum:

gamma rays

X-rays 1 nm - 1 pm

ultraviolet 380 nm - 1 nm

visible light 750 nm - 380 nm

infrared $25 \mu m - 750 nm$

microwaves 1 mm - $25 \mu m$

radio waves > 1 mm

The peak wavelength of this star is

$\lambda=7.25\cdot 10^{-8}m=72.5 nm$

Therefore, it falls in the ultraviolet region.

(c) No

The Keck telescopes is actually a system of 2 telescopes in the Keck Observatory, located in Mauna kea, Hawai.

The two telescopes, thanks to several instruments, are able to detect much of the electromagnetic radiation in the visible ligth and infrared parts of the spectrum. However, they are not able to detect light in the ultraviolet region: therefore, they cannot observe the star mentioned in the previous part of the problem.

7 0

3 years ago

A 1350 kg car travels at 12 m/s. What is it's kinetic energy

Lana71 [14]

Hello!

A 1350 kg car travels at 12 m/s. What is it's kinetic energy ?

We have the following data:

m (mass) = 1350 kg

v (velocity) = 12 m/s

KE (kinetic Energy) = ? (in Joule)

Formula to calculate kinetic energy:

$\boxed{KE = \dfrac{1}{2} *m*v^2}$