Name three forces involved in brushing your teeth.

Scientist who discovered that the nucleus contains neutrons in addition to protons.

ZanzabumX [31]

Answer: James Chadwick

:)

5 0

2 years ago

A girl exerts a horizontal force of 109 N on a crate with a mass of 31.2 kg. HINT (a) If the crate doesn't move, what's the magn

vesna_86 [32]

Answer:

(a) Magnitude of static friction force is 109 N

(b) Minimum possible value of static friction is 0.356

Solution:

As per the question;

Horizontal force exerted by the girl, F = 109 N

Mass of the crate, m = 31.2 kg

Now,

(a) To calculate the magnitude of static friction force:

Since, the crate is at rest, the forces on the crate are balanced and thus the horizontal force is equal to the frictional force, f:

F = f = 109 N

(b) The maximum possible force of friction between the floor and the crate is given by:

$f_{m} = \mu_{s}N$

where

N = Normal reaction = mg

Thus

$f_{m} = \mu_{s}mg$

For the crate to remain at rest, The force exerted on the crate must be less than or equal to the maximum force of friction.

$f\leq f_{m}$

$f \leq \mu_{s}mg$

$109 \leq \mu_{s}\times 31.2\times 9.8$

$\mu_{s}\geq 0.356$

7 0

2 years ago

8 th Grade Physical Science Worksheet Part A: Read the scenario and answer the questions. David read that Fox brake pads and Bes

svet-max [94.6K]

Okokokokokokokokok!OK?

4 0

2 years ago

Define temperature using molecular theory

Kitty [74]

Answer: At the molecular level, temperature is related to the random motions of the particles (atoms and molecules) in matter. ... The temperature of the puddle, or of any object, is a measure of the average of the individual translational energies of all of its atoms or molecules.

Explanation: my science teacher already tought us this

3 0

2 years ago

Read 2 more answers

A sheet of glass is coated with a 500-nm-thick layer of oil (n = 1.42).

tamaranim1 [39]

Answer:

a) 473.33 nm 

b) 568 nm and 406 nm

c) bluish green and blue

Explanation:

a) As the light traverses the layer of oil it first reflects at the front surface of the oil. Here the index of refraction increases from that of air to that of the oil , so a phase change occurs. The light then reflects from the rear surface of oil. The index of refraction increases from that of the oil to that of the glass , so again a phase change occurs. Thus two phase changes occur.

In thin-film interference with 0 or 2 phase changes, condition for constructive interference is:

2t=mλ/n

So:

λ= 2tn/m

For m=1

λ=1420 nm

For m=2

λ=710 nm

For m=3

λ=473.33 nm

For m=4

λ=355 nm

Thus the only wavelength in the visible spectrum (400 - 700 nm) that will give constructive interference is 473.33 nm 

b)

In thin-film interference with 0 or 2 phase changes, condition for destructive interference is:

2t=(m+1/2)λ/n=(2m+1)*λ/2n

so;

λ=4tn/(2m+1)

For m=1

λ=946.667 nm

For m=2

λ=568 nm

For m=3

λ=405.33 nm

For m=4

λ=315.56 nm

Thus the wavelengths in the visible spectrum (400 to 700 nm) that will give destructive interference are 568 nm and 406 nm

c) The color of reflected light is bluish green since the wavelength is 473.3 nm . We know that the colors of reflected and transmitted light are complimentary to each other.Thus the color of transmitted light is blue (due to the combination of wavelengths 568 nm (green) and 406 nm (deep violet).

5 0

3 years ago