Which answer is right? thanks if u help me! :)

Physics

2 answers:

WINSTONCH [101]3 years ago

8 0

Answer: I believe the answer is 7.5 x 10^(14)Hz or 7.5E14Hz

Explanation: the formula for frequency is speed of the wave divided by the wavelength

f= c/wavelength

f- frequency

c-speed

(3 x 10^(8)) x (400 x 10^(-9))= 750,000,000,000,000 or 7.5E14 or 7.5 x10^(14)

enyata [817]3 years ago

7 0

Answer:7.5 x 10* 14

Explanation:

You might be interested in

Whoever answers correctly gets brainlist!

UNO [17]

Infared = used by police

gamma = short wavelength

radio = largest wavelength

visible = only ones we can see

5 0

2 years ago

Read 2 more answers

A trait of an organism that helps it survive in its environment is calles

kompoz [17]

Answer is adaptation. An organism develops a trait over time to help survive in its environment called an adaptation. You could take a giraffe for example. A long time ago giraffes actually had short necks, but now since their food is higher they soon developed a longer neck and this is what we now see in the present. This goes for any artic animal. Polar bears and seals have a white fur adaptation to help them blend in with their environment. A chameleon changes colors in order to hide from predators and sneak up on prey. These are all adaptations

7 0

2 years ago

Read 2 more answers

A 20.0-N weight slides down a rough inclined plane which makes an angle of 30 degree with the horizontal. The weight starts from

Ulleksa [173]

Answer:

$1270.64\ \text{J}$

Explanation:

m = Mass of object = $\dfrac{mg}{g}$

mg = Weight of object = 20 N

g = Acceleration due to gravity = $9.81\ \text{m/s}^2$

v = Final velocity = 15 m/s

u = Initial velocity = 0

d = Distance moved by the object = 150 m

$\theta$ = Angle of slope = $30^{\circ}$

f = Force of friction

fd = Work done against friction

The force balance of the system is

$\dfrac{1}{2}m(v^2-u^2)=(mg\sin\theta-f)d\\\Rightarrow \dfrac{1}{2}mv^2=mg\sin\theta d-fd\\\Rightarrow fd=mg\sin\theta d-\dfrac{1}{2}mv^2\\\Rightarrow fd=20\times \sin 30^{\circ}\times 150-\dfrac{1}{2}\times \dfrac{20}{9.81}\times 15^2\\\Rightarrow fd=1270.64\ \text{J}$