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3 years ago

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:

Explanation:

M-A=N

Mass-Atomic #= Neutrons

81-28= 53

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A student compared some soccer players to the atoms in the gaseous state. Which of the following activities were the soccer play

tensa zangetsu [6.8K]

Answer:

The answer will be D

Explanation:

I choose answer C and got it wrong on the test. Also Liquid atoms vibrate fast and slide past each other. what answer C shows is a gas.

8 0

2 years ago

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Consider the motion of a 4.00-kg particle that moves with potential energy given by U(x) = + a) Suppose the particle is moving w

gtnhenbr [62]

Correct question:

Consider the motion of a 4.00-kg particle that moves with potential energy given by

$U(x) = \frac{(2.0 Jm)}{x}+ \frac{(4.0 Jm^2)}{x^2}$

a) Suppose the particle is moving with a speed of 3.00 m/s when it is located at x = 1.00 m. What is the speed of the object when it is located at x = 5.00 m?

b) What is the magnitude of the force on the 4.00-kg particle when it is located at x = 5.00 m?

Answer:

a) 3.33 m/s

b) 0.016 N

Explanation:

a) given:

V = 3.00 m/s

x1 = 1.00 m

x = 5.00

$u(x) = \frac{-2}{x} + \frac{4}{x^2}$

At x = 1.00 m

$u(1) = \frac{-2}{1} + \frac{4}{1^2}$

= 4J

Kinetic energy = (1/2)mv²

$= \frac{1}{2} * 4(3)^2$

= 18J

Total energy will be =

4J + 18J = 22J

At x = 5

$u(5) = \frac{-2}{5} + \frac{4}{5^2}$

$= \frac{4-10}{25} = \frac{-6}{25} J$

= -0.24J

Kinetic energy =

$\frac{1}{2} * 4Vf^2$

= 2Vf²

Total energy =

2Vf² - 0.024

Using conservation of energy,

Initial total energy = final total energy

22 = 2Vf² - 0.24

Vf² = (22+0.24) / 2

$Vf = \sqrt{frac{22.4}{2}$

= 3.33 m/s

b) magnitude of force when x = 5.0m

$u(x) = \frac{-2}{x} + \frac{4}{x^2}$

$\frac{-du(x)}{dx} = \frac{-d}{dx} [\frac{-2}{x}+ \frac{4}{x^2}$

$= \frac{2}{x^2} - \frac{8}{x^3}$

At x = 5.0 m

$\frac{2}{5^2} - \frac{8}{5^3}$

$F = \frac{2}{25} - \frac{8}{125}$

= 0.016N

8 0

3 years ago

Which of the following units are used to describe acceleration?

Pavel [41]

Answer:

m/s2 m/s

Explanation:

7 0

3 years ago

A traffic light of weight 100 N is supported by two ropes that make 30-degree angle with the horizontal. What is the vertical co

alina1380 [7]

Answer:

$T_{vertical} = 50 N$

Explanation:

given,

traffic light weight = 100 N

angle at which the rope is supported = 30°

vertical component of force = ?

$2 T sin \theta= W$

$2 T sin 30^0= 100$

$T = \dfrac{100}{2 sin 30^0}$

$T = 100\ N$

$T_{vertical} = T sin 30^0$

$T_{vertical} = 100\times \dfrac{1}{2}$

$T_{vertical} = 50 N$

5 0

3 years ago

A metal object with a mass of 19g is heated to 96c, then transferred to a calorimeter containg 75g of water at 18c. the water an

avanturin [10]

Let us say that Cp is the specific heat of the metal object. Then we do a heat balance (heat lost by metal = heat gained by water):

- 19g * Cp * (22degC – 96degC) = 75g * 4.184J/g degC * (22degC – 18degC)

Cp = 0.893 J/g degC

6 0

2 years ago

Read 2 more answers