PHYSICS
MIDDLE SCHOOL

(B) The molecules of one substance break down in the other.

(C) Different samples of a single mixture have different characteristics.

(D) One substance can be separated from another through physical means.

Answer:

Answer:

Option D is right

Explanation:

Mixture is defined as a combination of different things in which the component elements are individually distinct.

i.e. only physically they are mixed and each substance retains its original characteristic even after mixing. For mixing, no heating or any other mode is required.

Hence out of the 4 option I option is not right since dissolution makes losing characteristic

B) is wrong since molecules cannot break down in physical mixing

C) is wrong as single mixture will have same characteristic

D) Is right One substance can be separated from another through physical means

Answer:

Answer: D) One substance can be separated from another through physical means.

Explanation:

Have a wonderfullllll day:)

HIGH SCHOOL

What is the excess charge on a conducting sphere of radius r = 0.31 m if the potential of the sphere is 1375 V and V = 0 at infinity?

Given Information:

Radius = r = 0.31 m

Potential difference = V = 1375 Volts

Required Information:

charge = q = ?

Answer:

q = 4.741x10⁻⁸ C

Solution:

Where k = 8.99x10⁹ N.m²/C² is the Coulomb's constant

Re-arranging the equation to find the q

q = (1375*0.31)/8.99x10⁹

q = 4.741x10⁻⁸ C = 47.41 nC

MIDDLE SCHOOL

What is another way of saying “getting the smallest possible force”?

Answer:

MOMENTUM

Explanation:

another way of saying getting the smallest force possible is the word " MOMENTUM".

momentum is the ability to keep maintaining,incresing or itself developing to move at constant speed or to increase the speed.

MIDDLE SCHOOL

A 2 N apple is hanging from a branch. What is the action force? A. the net force B. the normal force C. a 2 N upward force D. a 2 N downward force

Answer:

2 N downward force

Explanation:

Since apple is hanging,so due to gravity,according to Newton second law,gravitational effect is due to the weight of the object and is acting downward.So action force is due to gravitational effects.

Hence,2 N will acting in downward direction due to gravity.

Answer: a downward force

HIGH SCHOOL

1) The moon has a mass of 7.4 × 1022 kg and completes an orbit of radius 3.8 × 108 m about every 28 days. The Earth has a mass of 6 × 1024 kg and completes an orbit of radius 1.5 × 1011 m every year. What is the speed of the Moon in its orbit? Answer in units of m/s. 2) What is the kinetic energy of the Moon in orbit?

Answer in units of J.

3. What is the kinetic energy of the Earth? Answer in units of J.

What is the speed of the Moon in its orbit? Answer in units of m / s.

By definition we have that the speed in a circular movement is given by:

v = w * r

We then have to replace the values:

v = ((2 * pi) / (28 * (24/1) * (3600/1))) * (3.8 * 10 ^ 8)

v = 986.94 m / s

2) What is the kinetic energy of the Moon in orbit? Answer in units of J.

By definition, the kinetic energy is given by:

K = (1/2) * (m) * (V ^ 2)

Where,

m: mass

V: speed

Substituting the values we have:

K = (1/2) * (7.4 * 10 ^ 22) * ((986.94) ^ 2)

K = 3.60E + 28 J

3. What is the kinetic energy of the Earth? Answer in units of J.

First we must find the speed of the earth:

v = ((2 * pi) / ((1) * (365/1) * (24/1) * (3600/1))) * (1.5 * 10 ^ 11)

v = 29886 m / s

By definition, the kinetic energy is given by:

K = (1/2) * (m) * (V ^ 2)

Where,

m: mass

V: speed

Substituting the values we have:

K = (1/2) * (6 * 10 ^ 24) * ((29886) ^ 2)

K = 2.67E + 33 J

By definition we have that the speed in a circular movement is given by:

v = w * r

We then have to replace the values:

v = ((2 * pi) / (28 * (24/1) * (3600/1))) * (3.8 * 10 ^ 8)

v = 986.94 m / s

2) What is the kinetic energy of the Moon in orbit? Answer in units of J.

By definition, the kinetic energy is given by:

K = (1/2) * (m) * (V ^ 2)

Where,

m: mass

V: speed

Substituting the values we have:

K = (1/2) * (7.4 * 10 ^ 22) * ((986.94) ^ 2)

K = 3.60E + 28 J

3. What is the kinetic energy of the Earth? Answer in units of J.

First we must find the speed of the earth:

v = ((2 * pi) / ((1) * (365/1) * (24/1) * (3600/1))) * (1.5 * 10 ^ 11)

v = 29886 m / s

By definition, the kinetic energy is given by:

K = (1/2) * (m) * (V ^ 2)

Where,

m: mass

V: speed

Substituting the values we have:

K = (1/2) * (6 * 10 ^ 24) * ((29886) ^ 2)

K = 2.67E + 33 J

Mass of the moon Mm = 7.4 Ă— 10^22 kg

Moon orbital radius Rm= 3.8 Ă— 10^8 m

Time Tm = 28 days = 2.419 x 10^6

Mass of the Earth Me= 6 Ă— 10^24 kg

Earth orbital radius Re= 1.5 Ă— 10^11 m

Time Te = 365 days = 3.154 x 10^7

Length of Moon orbit Lm = 2 x pi x Rm = 2 x 3.14 x 3.8 Ă— 10^8 m = 23.86 x

10^8 m

Moon orbital velocity Vm = Lm / Tm = 23.86 x 10^8 m / 2.419 x 10^6 = 986.5 m/s

Kinetic Energy of the Moon = 1/2 x Mm x Vm^2 = 0.5 x 7.4 Ă— 10^22 x 986.5^2

Kinetic Energy of the Moon = 36 x 10^27 J

Length of earth orbit Le = 2 x pi x Re = 2 x 3.14 x 1.5 Ă— 10^11 = 9.42 x 10^11 m

Earth orbital Velocity Ve = Lm / Tm = 9.42 x 10^11 / 3.154 x 10^7 = 29866 m/s

Kinetic Energy of the Earth = 1/2 x Me x Ve^2 = 0.5 x 6 Ă— 10^24 x 29866^2

Kinetic Energy of the Earth = 26.76 x 10^32 J

Moon orbital radius Rm= 3.8 Ă— 10^8 m

Time Tm = 28 days = 2.419 x 10^6

Mass of the Earth Me= 6 Ă— 10^24 kg

Earth orbital radius Re= 1.5 Ă— 10^11 m

Time Te = 365 days = 3.154 x 10^7

Length of Moon orbit Lm = 2 x pi x Rm = 2 x 3.14 x 3.8 Ă— 10^8 m = 23.86 x

10^8 m

Moon orbital velocity Vm = Lm / Tm = 23.86 x 10^8 m / 2.419 x 10^6 = 986.5 m/s

Kinetic Energy of the Moon = 1/2 x Mm x Vm^2 = 0.5 x 7.4 Ă— 10^22 x 986.5^2

Kinetic Energy of the Moon = 36 x 10^27 J

Length of earth orbit Le = 2 x pi x Re = 2 x 3.14 x 1.5 Ă— 10^11 = 9.42 x 10^11 m

Earth orbital Velocity Ve = Lm / Tm = 9.42 x 10^11 / 3.154 x 10^7 = 29866 m/s

Kinetic Energy of the Earth = 1/2 x Me x Ve^2 = 0.5 x 6 Ă— 10^24 x 29866^2

Kinetic Energy of the Earth = 26.76 x 10^32 J