Physics, calculating net force. Please work it out for me

Answer:

See explanation

Explanation:

a) Formula for the mass of the sample that remains after t years = N= Noe^-kt

Where;

N = mass at time t years

No = mass at time t= 0

k = decay constant

t = time taken

So,

N = 100e^-kt

b) First,

t1/2 = -ln(1/2)/k

t1/2 = 0.693/k

t1/2 = half life of radium-226 =1590 years

1590 = 0.693/k

k = 0.693/1590

k = 4.36 * 10^-4

So,

N= 100e^-(4.36 * 10^-4 * 1000)

N= 65 mg

c) From

N = 100e^-kt

40 = 100e^-(4.36 * 10^-4t)

40/100 = e^-(4.36 * 10^-4t)

0.4 = e^-(4.36 * 10^-4t)

ln(0.4) = ln(e^-(4.36 * 10^-4t))

-0.9163 = -4.36 * 10^-4t

t = 0.9163/4.36 * 10^-4

t = 2102 years

Answer:

The amplitude decreases

Explanation:

From the inverse square law, we know that;

I ∝ 1/d²

Where;

I is intensity

d is distance

Also, we know that;

A² ∝ I

Where A is amplitude

Thus, we can say that;

A ∝ 1/d²

Thus, amplitude is inversely proportional to the distance.

So the larger the distance, the lesser the amplitude and the lesser the distance, the higher the amplitude.

Thus, as you move farther from the speaker the distance increases and therefore the amplitude decreases

This question is incomplete, the missing image is uploaded along this answer.

Answer:

the coefficient of friction is 0.32

Explanation:

 Given the data in the question;

we make use of kinematic equation of motion;

ω = ω₀ + ∝t

we substitute

ω = ( 0 rad/s ) + ( 0.4 rad/s² )( 9.903 s )

ω = 3.9612 rad/s

The centripetal force acting on the sample is;

Fc = mrω²

from the image; r = 200 mm = 0.2 m

so we substitute

Fc = m(0.2 m ) ( 3.9612 rad/s )²

Fc = (3.13822 m/s²)m

we know that the frictional force between the two materials should be providing the necessary centripetal force to rotate the sample object;

f = Fc

μN = Fc

μmg = (3.13822 m/s²)m

μ = (3.13822 m/s²)m / mg

μ = (3.13822 m/s²) / g

acceleration due to gravity g = 9.8 m/s²

so

μ = (3.13822 m/s²) / 9.8 m/s²

μ = 0.32

Therefore, the coefficient of friction is 0.32

NASA's Mars Pathfinder mission, launched in 1996, put the first free-moving rover—called Sojourner—on the planet. ... Together, these missions have shown scientists that Mars is an active planet that is rich in the ingredients needed for life as we know it—water, organic carbon, and an energy source

Answer:

The sun and the stars

Explanation:

I hope this helps!

Answer:

Northstar & North Pole

Explanation:

yyggggggggggggggg

Answer:

20.49 N

Explanation:

From the question given above, the following data were obtained:

Power (P) = 0.824 hp

Velocity (v) = 30 m/s

1 h = 746 W

Force (F) =?

Next, we shall convert 0.824 hp to Watts (W). This can be obtained as follow:

1 h = 746 W

Therefore,

0.824 hp = 0.824 hp × 746 W / 1 h

0.824 hp = 614.704 W

Finally, we shall determine the force as follow:

Power (P) = 614.704 W

Velocity (v) = 30 m/s

Force (F) =?

P = F × v

614.704 = F × 30

Divide both side by 30

F = 614.704 / 30

F = 20.49 N

Answer:

momentum = mass * velocity ... kg•m/s

acceleration = v / t = 200 m/s / 11 ms ... m/s^2

force = mass * acceleration = .02 kg * (200 m/s / 11 ms) N

Explanation:

Answer:

"Cannot be determined," if that's an answer choice. It depends on the velocities of both objects, since momentum=mass*velocity.

Explanation:

Answer:

[tex]3.031\times 10^{-5}\ \text{m}[/tex]

Explanation:

[tex]y[/tex] = Distance between central maxima and first minimum

m = Order = 1

d = Thickness of hair

[tex]\lambda[/tex] = Wavelength = 632.8 nm

L = Distance between light source and screen = 1.25 m

Width of central maximum is given by

[tex]2y=5.22\times 10^{-2}\\\Rightarrow y=\dfrac{5.22\times 10^{-2}}{2}\\\Rightarrow y=0.0261\ \text{m}[/tex]

Distance between central maxima and first minimum is given by

[tex]y=L\tan\theta_{min}\\\Rightarrow \tan\theta_{min}=\dfrac{y}{L}\\\Rightarrow \tan\theta_{min}=\dfrac{0.0261}{1.25}\\\Rightarrow \theta_{min}=\tan^{-1}0.02088\\\Rightarrow \theta_{min}=1.1962^{\circ}[/tex]

Since [tex]\theta[/tex] is small [tex]\tan\theta_{min}=\sin\theta_{min}[/tex]

[tex]\sin\theta_{min}=\dfrac{m\lambda}{d}\\\Rightarrow d=\dfrac{m\lambda}{\sin\theta}\\\Rightarrow d=\dfrac{1\times 632.8\times 10^{-9}}{\sin1.1962^{\circ}}\\\Rightarrow d=3.031\times 10^{-5}\ \text{m}[/tex]

The strand of hair is [tex]3.031\times 10^{-5}\ \text{m}[/tex] thick.

Answer:

Potential Energy

Explanation:

Answer:

B = An 8 kg book at a height of 3 m

Answer:

checking your e-mail on your computer using a coffee's shop WiFi. No need radio waves for this.

Explanation:

Because you are only checking it, nothing else.

Answer:

A)

the minimum stopping distance for which the load will not slide forward relative to the truck is 14 m

B)

data that were not necessary to the solution are;

a) mass of truck and b) mass of load

Explanation:

Given that;

mass of load [tex]m_{LS}[/tex] = 10000 kg

mass of flat bed [tex]m_{FB}[/tex] = 20000 kg

initial speed of truck [tex]v_{0}[/tex] = 12 m/s

coefficient of friction between the load sits and flat bed μs = 0.5

A) the minimum stopping distance for which the load will not slide forward relative to the truck.

Now, using the expression

Fs,max = μs [tex]F_{N}[/tex]     -------------let this be equation 1

where [tex]F_{N}[/tex] = normal force = mg

so

Fs,max = μs mg

ma[tex]_{max}[/tex] = μs mg

divide through by mass

a[tex]_{max}[/tex] = μs g    ---------- let this be equation 2

in equation 2, we substitute in our values

a[tex]_{max}[/tex] = 0.5 × 9.8 m/s²

a[tex]_{max}[/tex] = 4.9 m/s²

now, from the third equation of motion

v² = u² + 2as

[tex]v_{f}[/tex]² = [tex]v_{0}[/tex]² + 2aΔx

where [tex]v_{f}[/tex] is final velocity ( 0 m/s )

a is acceleration( - 4.9 m/s² )

so we substitute

(0)² = (12 m/s)² + 2(- 4.9 m/s² )Δx

0 = 144 m²/s² - 9.8 m/s²Δx

9.8 m/s²Δx = 144 m²/s²

Δx = 144 m²/s² /  9.8 m/s²

Δx = 14 m

Therefore, the minimum stopping distance for which the load will not slide forward relative to the truck is 14 m

B) data that were not necessary to the solution are;

a) mass of truck and b) mass of load

Answer:

the fundamental frequency produced by the open pipe is 120.78 Hz

Explanation:

Given;

length of the open pipe, L = 1.42 m

speed of sound in air, v = 343 m/s

The length of the open pipe for the fundamental frequency is equivalent to half of wavelength;

[tex]L = \frac{\lambda}{2} \\\\\lambda = 2L[/tex]

The fundamental frequency produced by the open pipe is calculated as;

[tex]f_o = \frac{v}{\lambda} \\\\f_o = \frac{v}{2L} \\\\f_o = \frac{343}{2 \times 1.42} \\\\f_o = 120.78 \ Hz[/tex]

Therefore, the fundamental frequency produced by the open pipe is 120.78 Hz

The answer is b I just took the test

Neuroticism, psychoticism, and extraversion are the three dominant personality traits according to Hans Eysenck.

Eysenck's theory of personality is based on three logical attributes namely:  

a) Introversion vs. extroversion – Extroversion leads to sociable life , while introversion causes need of being alone and limited interactions

b) Neuroticism vs. stability – Neuroticism leads to anxiousness and an overactive sympathetic nervous system while stability leads to emotional stability.

c) Nsychoticism vs. socialization. - psychoticism  leads to independent thinking, and hostility. While socialization leads to co-operative and conventional behaviour.  

Therefore Neuroticism, psychoticism, and extraversion are the three dominant personality traits according to Hans Eysenck.

To know more about Hans Eysenck's theory follow

https://brainly.com/question/11912668

#SPJ2

Answer:

25000J

Explanation:

Formula : Q = m×c×Δt

Q=Heat energy

m= mass

c=specific heat capacity

ΔT = change in temperature.

Q=M x C for this question.

Specific heat capacity = 2500 J/Kg

Mass = 10kg

2500 x 10 = 25000 J

Answer:

a) the weight of the person is 170.5 lbf

b) weight of the astronaut on the moon is 28.2 lbf

Explanation:

Given the data in the question;

a)

we know that;

weight on the surface of the earth = m[tex]g_{earth[/tex]

given that m = 170.5 lbm and g = 32.174 ft/s²

we substitute

weight on the surface of the earth =  170.5 lbm × 32.174 ft/s²

= 5485.667 lbm-ft/s²

1 lbf = 32.174 lbm-ft/s²

so

weight on the surface of the earth = (5485.667 / 32.174) lbf

weight on the surface of the earth = 170.5 lbf

Therefore, the weight of the person is 170.5 lbf

b)

given that;

weight on the surface of the earth = m[tex]g_{moon[/tex]

m = 170.5 lbm and g = 5.32 ft/s²

weight on the surface of the earth = 170.5 lbm × 5.32 ft/s²

= 907.06 lbm-ft/s²

1 lbf = 32.174 lbm.ft/s²

weight on the surface of the earth = ( 907.06 / 32.174 ) lbf

weight on the surface of the earth = 28.2 lbf

Therefore, weight of the astronaut on the moon is 28.2 lbf

Answer:

Six purposes of government: to form a more perfect union; establish justice; insure domestic tranquility; provide for the common defense; promote the general welfare; secure the blessings of liberty now and in the future.

Explanation:

Answer:

The correct answer is - 1240 newtons; 278.763 lbs.

Explanation:

Answer:

it is long.

Explanation:

I know the answer but I don't know how to explain it

Answer:

The correct option is b: 30 N.

Explanation:

First, we need to find the acceleration due to gravity (a):

[tex] y_{f} - y_{0} = v_{o}t - \frac{1}{2}a(\Delta t)^{2} [/tex]   (1)

Where:

[tex]y_{f}[/tex]: is the final vertical position (obtained from the graph)

[tex]y_{0}[/tex]: is the initial vertical position (obtained from the graph)

v₀: is the initial speed = 0 (it is released from rest)

Δt: is the variation of time (from the graph)

From the graph, we can take the following values of height and time:

t₀ = 0 s → [tex]t_{f}[/tex] = 5 s

y₀ = 300 m → [tex]y_{f}[/tex] = 225 m

Now, by entering the above values into equation (1) and solving for "a" we have:

[tex] a = 2\frac{y_{0} - y_{f}}{(t_{f} - t_{0})^{2}} = 2\frac{300 m - 225 m}{(5 s - 0)^{2}} = 6 m/s^{2} [/tex]

Finally, the weight of the object is:

[tex] W = ma = 5 kg*6 m/s^{2} = 30 N [/tex]

Therefore, the correct option is b: 30 N.

I hope it helps you!                                                                                                            

Answer:

30°

Explanation:

The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.

∠i = ∠r

so as ∠i = 30°

∠r will also be 30°

Answer:

C. Plate Tectonics

Explanation:

The theory of plate tectonics is when the lithosphere is separated into plates. These plates move over or float over the asthenosphere. The movement of these plates cause earthquakes and can interact with the volcanic activity.

Answer:

[tex]23796.19\ \text{N}[/tex]

[tex]0.0002032\ \text{s}[/tex]

Explanation:

F = Force

s = Displacement = 6.3 cm

m = Mass of bullet = 7.8 g

v = Velocity of bullet = 620 m/s

t = Time taken

Work done is given by

[tex]W=Fs[/tex]

Kinetic energy is given by

[tex]K=\dfrac{1}{2}mv^2[/tex]

Using work energy considerations we get

[tex]Fs=\dfrac{1}{2}mv^2\\\Rightarrow F=\dfrac{1}{2s}mv^2\\\Rightarrow F=\dfrac{1}{2\times 0.063}\times 7.8\times 10^{-3}\times 620^2\\\Rightarrow F=23796.19\ \text{N}[/tex]

The average force that stops the bullet is [tex]23796.19\ \text{N}[/tex].

Force is given by

[tex]F=m\dfrac{v-u}{t}\\\Rightarrow t=m\dfrac{v-u}{F}\\\Rightarrow t=7.8\times 10^{-3}\times \dfrac{620}{23796.19}\\\Rightarrow t=0.0002032\ \text{s}[/tex]

The time taken to stop the bullet is [tex]0.0002032\ \text{s}[/tex].

Answer:

Distillation separates a liquid from a solution. For example, water can be separated from salty water by simple distillation. This method works because the water evaporates from the solution, but is then cooled and condensed into a separate container. The salt does not evaporate and so it stays behind.

Answer:

[tex]31.035^{\circ}[/tex]

Explanation:

x = Displacement in x direction = 5.34 m

t = Time taken to travel the displacement

y = Displacement in y direction = 0

u = Initial velocity of ball = 7.7 m/s

g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]

Displacement in x direction is given by

[tex]x=u\cos\theta t\\\Rightarrow t=\dfrac{5.34}{7.7 \cos\theta}[/tex]

Displacement in y direction is given by

[tex]y=u\sin\theta t-\dfrac{1}{2}gt^2\\\Rightarrow 0=7.7\sin\theta \dfrac{5.34}{7.7\cos\theta}-\dfrac{1}{2}\times 9.81 (\dfrac{5.34}{7.7\cos\theta})^2\\\Rightarrow 0=7.7\sin\theta-4.905\times \dfrac{5.34}{7.7\cos\theta}\\\Rightarrow 0=7.7^2\sin\theta \cos\theta-4.905\times 5.34\\\Rightarrow 0=7.7^2\dfrac{\sin2\theta}{2}-4.905\times 5.34\\\Rightarrow 0=7.7^2\sin2\theta-4.905\times5.34\times 2\\\Rightarrow \sin2\theta=\dfrac{4.905\times 5.34\times 2}{7.7^2}\\\Rightarrow 2\theta=\sin^{-1}\dfrac{4.905\times 5.34\times 2}{7.7^2}[/tex]

[tex]\Rightarrow \theta=\dfrac{62.07}{2}\\\Rightarrow \theta=31.035^{\circ}[/tex]

The angle at which the ball was thrown is [tex]31.035^{\circ}[/tex].