Calculate the wavelength of a wave if 5 complete waves occupy a length of 20m

A ray moving in plastic at 62.9 deg enters water, where it bends to 70.9 deg. What is the index of refraction of the plastic?

DedPeter [7]

Answer:

refractive index of plastic is 1.42

Explanation:

When light ray enters from one medium to other medium then due to transition of light it bends away or towards the normal, this phenomenon is known as refraction of light

So here we know that

$n_1 sin i = n_2 sin r$

here we have

$n_2 = \frac{4}{3}$

$i = 62.9^o$

$r = 70.9^o$

now we have

$n_1 sin62.9 = (\frac{4}{3}) sin70.9$

$n_1 = 1.42$

7 0

3 years ago

Den pushes a desk 400 cm across the floor. He exerts a force of 10 N for 8 s to move the desk. What is his power output? (Power:

White raven [17]

Answer:

5 W

Explanation:

The formula of the power is:

● P = W/t

W is the work and t is the time needed to do it(in seconds)

Let's calculate first the work that the force exerced:

W = Vector F . Vector d

D is the distance ( here 400 cm wich is 4 m)

Make a representation to see how are the vectors F and V.(picture below)

The vector F and d are colinear since Den is pushing the desk on the ground.

● W = 4 × 10 = 40 J

J is Joule

■■■■■■■■■■■■■■■■■■■■■■■■■■

● P = W / t

● P = 40/ 8

● P = 5 W

7 0

3 years ago

PLEASE HELP MEEEEEE!!!!!!!!!!!!!!!!!!

Simora [160]

You would need to freeze it in a freezer. Hope this helps if it does could I have brainlist thanks

5 0

2 years ago

Read 2 more answers

A horizontal wire is hung from the ceiling of a room by two massless strings. The wire has a length of 0.11 m and a mass of 0.01

AnnZ [28]

Answer:

Explanation:

The magnetic force acting horizontally will deflect the wire by angle φ from the vertical

Let T be the tension

T cosφ = mg

Tsinφ = Magnetic force

Tsinφ = BiL , where B is magnetic field , i is current and L is length of wire

Dividing

Tanφ = BiL / mg

= .055 x 29 x .11 / .010 x 9.8

= 1.79

φ = 61° .

Tension T = mg / cosφ

= .01 x 9.8 / cos61

= .2 N .

5 0

3 years ago

Young's Modulus refers to changes in the: a- Volume b- Length c- Body layers

bekas [8.4K]

<u>Answer:</u> The correct answer is Option b.

<u>Explanation:</u>

Young's Modulus is defined as the ratio of stress acting on a substance to the amount of strain produced.

Stress is defined as force per unit area and strain is defined as proportional deformation in a material.

The equation representing Young's Modulus is:

$Y=\frac{F/A}{\Delta l/l}=\frac{Fl}{A\Delta l}$

where,

Y = Young's Modulus

F = force exerted by the weight

l = length of wire

A = area of cross section

$\Delta l$ = change in length

Hence, the correct answer is Option b.

6 0

3 years ago