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ryzh [129]
3 years ago
8

How many neutrons does element X have if it’s atomic number is 28 and it’s mass number is 81?

Physics
2 answers:
Sedaia [141]3 years ago
8 0

The answer is 53,hope this help

Sauron [17]3 years ago
3 0

Answer:

53

Explanation:

M-A=N

Mass-Atomic #= Neutrons

81-28= 53

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You are on an interstellar mission from the Earth to the 8,7 light-years distant star Sirius. Your spaceship can travel with 70%
marishachu [46]

Answer:

Time = 12.43 years

Mass = 4.71.43kg

Explanation:

Given the following :

Distance = 8.7 light years

Speed = 70% the speed of light

Diameter = 6m

Lengtg = 25m

Density = 1 hydrogen atom/m^3

Mass of proton(Me) = 1.673x 10^-27

A.) time it takes your spaceship to reach Sirius :

From the relation: Speed = (distance / time)

Time = distance / speed

Time = (70/100) × 1 light year

Distance = 8.7 light years

Time = 8.7 / 0.7 = 12.4285 years

Time = 12.43 years

B.) Mass of inter-stellar gas that collides with the spaceship can be calcuted by finding the product of the surface area of the cylindrical space ship and the mass of proton.

That is ;

surface area * mass of proton

Surface area of a cylinder = 2πrh + πr^2×Me

= 2πrh + Me×πr^2)

=( 2 × 22/7 × 3 × 25) + (22/7 × 3^2 × 1.673 * 10^-27)

= 2× 235.714 + 28.285) × 1.673 * 10^-27

= 471.428 + 47.31 * 10^-27

= 471.428 + 4.73 × 10^-26

= 4.71.43kg approximately

7 0
3 years ago
A student observed a sample of water in three states of matter. The student should describe the liquid water as a state of matte
Nadya [2.5K]

Answer:

B. Less volume than a solid state

6 0
3 years ago
B)
Vlad1618 [11]

Answer:

a) 16m/s b) 192m

Explanation:

v1=32m/s a=-2m/s^2 t=8s v2=? d=??

a) I will use this equation v2= v1 + a*t

v2= 32m/s + -2m/s^2 * 8s

v2= 32m/s + -16m/s

v2= 16m/s

b) v2^2=v1^2 + 2ad

rearranging

v2^2-v1^2=2ad

v2^2-v1^2/2= a d

v2^2-v1^2/2a=d

16m/s^2 - 32m/s^2/ 2 x-2m/s^2 =d

d=192m

5 0
2 years ago
What physical property makes metal pots good for cooking
bonufazy [111]
The metal conducts the heat, which makes cooking easier.
5 0
3 years ago
6. several light bulbs are connected in series across a 115 v source
Natalka [10]

Explanation:

a) I = V / R

1.70 = 115 / R

R = 115 / 1.70

R = 67.647

R = 67.65 ohms

Therefore, equivalent resistance is 67.65 ohms

b) Equivalent resistance of circuit from above sum is 67.65 ohms

Given resistance of each bulb is 1.50 ohms

Number bulbs = Equivalent resistance / Resistance of each bulb

= 67.65 / 1.50

= 45

8 0
2 years ago
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