A black T-shirt is warmer in the summertime than a white T-shirt because the black T-shirt
A. Is reflecting all wavelengths of light.
B. Absorbs violet light, the highest energy wavelength.
C. Is absorbing all wavelengths of light. D. Doesn’t absorb red, the longest wavelength.

Answer:

[tex]{ \bf{v = u + at}} \\ 50 = 20 + (a \times 10) \\ 30 = 10a \\ { \tt{acceleration = 3 \: {ms}^{ - 2} }}[/tex]

Answer: 11.36 m

Explanation:

Given

Mass of roller coaster is m=1200 kg

Initial speed of roller coaster is v=15 m/s

Energy at bottom and at the top is same i.e.

[tex]\Rightarrow \dfrac{1}{2}mv^2=mgh\\\\\Rightarrow \dfrac{1}{2}\times 1200\times 15^2=1200\times 9.8\times h\\\\\Rightarrow h=\dfrac{15^2}{2\times 9.8}\\\\\Rightarrow h=11.36\ m[/tex]

Thus, the highest point reach by the roller coaster is 11.36 m

Answer:

11.36m

Explanation:

It has to do with impulse or force. Just how the sheet has no volume. There is no sufficient impulse to crack the shell.

A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.

The sagging sheet gives the impact with the egg additional time, which prevents the egg from breaking when it is hurled against it. This lessens the force the egg would have applied to the wall had it been flung at it.

It has to do with impulse or force. Just how the sheet has no volume. There is no sufficient impulse to crack the shell.

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Answer:

you can measure by scale beacause we dont no sorry i cant help u but u can ask me some other Q

Answer:

it is answer of u are question

Answer:

sup qwertyasdfghjk

Explanation:

The final speed of the ball is 91.72 m/s.

Given the following data:

To find the final speed of the ball, we would use the following formula:

[tex]F = \frac{M(V - U)}{t}[/tex]

Where:

Substituting the parameters into the formula, we have;

[tex]15000 = \frac{0.145(V \;- \;40)}{0.0005}\\\\15000(0.0005) = 0.145(V \;- \;40)\\\\7.5 = 0.145V - 5.8\\\\0.145V = 7.5 + 5.8\\\\0.145V = 13.3\\\\V = \frac{13.3}{0.145}[/tex]

Final speed, V = 91.72 m/s

Therefore, the final speed of the ball is 91.72 m/s.

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Explanation:

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Answer:

Explanation:

Answer:

D

Explanation:

This is a great way to manage health.

A would be avoiding everything which isnt good.

B. would be emotionally draining and damaging to bottle feelings and ignore them.

C. is unhealthy to not exercise and eat food while doing nothing.

Answer:

Block A velocity is 23.33 m/s and the collission is not elastic.

Explanation:

a) m1v1 + m2v2 = m1v1' + m2v2'

Plug in givens

90+60=3v1'+80

solve for v1'= 23.33m/s

b) Find the initial and final kinetic energy of Block B

Ki= 1/2(4)(15)^2 + 1/2(3)(30)^2 = 1800 J

Kf= 1/2(4)(20)^2 + 1/2(3)*(23.33)^2= 1616.433J

Since Ki does not equal Kf the collision is not elastic

Answer:

The the linear speed (in m/s) of a point on the rim of this wheel at an instant=0.418 m/s

Explanation:

We are given that

Angular acceleration, [tex]\alpha=3.3 rad/s^2[/tex]

Diameter of the wheel, d=21 cm

Radius of wheel, [tex]r=\frac{d}{2}=\frac{21}{2}[/tex] cm

Radius of wheel, [tex]r=\frac{21\times 10^{-2}}{2} m[/tex]

1m=100 cm

Magnitude of total linear acceleration, a=[tex]1.7 m/s^2[/tex]

We have to find the linear speed  of a  at an instant when that point has a total linear acceleration with a magnitude of 1.7 m/s2.

Tangential acceleration,[tex]a_t=\alpha r[/tex]

[tex]a_t=3.3\times \frac{21\times 10^{-2}}{2}[/tex]

[tex]a_t=34.65\times 10^{-2}m/s^2[/tex]

Radial acceleration,[tex]a_r=\frac{v^2}{r}[/tex]

We know that

[tex]a=\sqrt{a^2_t+a^2_r}[/tex]

Using the formula

[tex]1.7=\sqrt{(34.65\times 10^{-2})^2+(\frac{v^2}{r})^2}[/tex]

Squaring on both sides

we get

[tex]2.89=1200.6225\times 10^{-4}+\frac{v^4}{r^2}[/tex]

[tex]\frac{v^4}{r^2}=2.89-1200.6225\times 10^{-4}[/tex]

[tex]v^4=r^2\times 2.7699[/tex]

[tex]v^4=(10.5\times 10^{-2})^2\times 2.7699[/tex]

[tex]v=((10.5\times 10^{-2})^2\times 2.7699)^{\frac{1}{4}}[/tex]

[tex]v=0.418 m/s[/tex]

Hence, the the linear speed (in m/s) of a point on the rim of this wheel at an instant=0.418 m/s

Answer: hello your question is incomplete below is the missing part

A spherical cavity is hollowed out of the interior of a neutral conducting sphere. At the center of the cavity is a point charge, of positive charge q.

answer:

- q

Explanation:

Since the spherical cavity was carved out of a neutral conducting sphere hence the electric field inside this conductor = zero

given that there is a point charge +q at the center of the spherical cavity hence for the electric field inside the conductor to be = zero the total surface charge qint on the wall of the cavity will be -q

Answer:

The force on the second piston is 5246.5 N .

Explanation:

Area of first piston, a = 3.002 cm^2

Area of second piston, A = 315 cm^2

Force on first piston, f = 50 N

let the force of the second piston is F.

According to the Pascal's law

[tex]\frac{f}{a} = \frac{F}{A}\\\\\frac{50}{3.002}=\frac{F}{315}\\\\F = 5246.5 N[/tex]

Answer:

2.70

Explanation:

pH = -log[H+]

pH = -log[2.0x10^-3]

pH = 2.70

Answer:

a) ΔT₁ = -4.68 N,   ΔT₂ = 4.68 N, b) ΔT₂ = 4.68 N, ΔT₁ = 4.68 N

Explanation:

In this exercise we will use Newton's second law.

         ∑F = m a

Let's start with the set of three cars

         F_total = M a

         F_total = M 0.12

where the total mass is the sum of the mass of each charge

          M = m₁ + m₂ + m₃

This is the force with which the three cars are pulled.

Now let's write this law for each vehicle

car 1

         F_total - T₁ = m₁ a

         T₁ = F_total - m₁ a

car 2

         T₁ - T₂ = m₂ a

         T₂ = T₁ - m₂ a

car 3

         T₂ = m₃ a

note that tensions are forces of action and reaction

a) They tell us that 39 kg is removed from car 2 and placed on car 1

         m₂’= m₂ - 39

         m₁'= m₁ + 39

         m₃ ’= m₃

they ask how much each tension varies, let's rewrite Newton's equations

The total force does not change since the mass of the set is the same F_total ’= F_total

car 1

           F_total ’- T₁ ’= m₁’ a

           T₁ ’= F_total - m₁’ a

           T₁ ’= (F_total - m₁ a) - 39 a

           T₁ '= T₁ - 39 0.12

           ΔT₁ = -4.68 N

car 2

           T₁’- T₂ ’= m₂’ a

           T₂ ’= T₁’- m₂’ a

           T₂ '= (T₁'- m₂ a) + 39 a

           T₂ '= T₂ + 39 0.12

           ΔT₂ = 4.68 N

b) in this case the masses remain

            m₁ '= m₁

           m₂ ’= m₂ - 39

           m₃ ’= m₃ + 39

we write Newton's equations

car 3

          T₂ '= m₃' a

          T₂ ’= (m₃ + 39) a

          T₂ '= m₃ a + 39 a

          T₂ '= T₂ + 39 0.12

          ΔT₂ = 4.68 N

car 1

            F_total - T₁ ’= m₁’ a

            T₁ ’= F_total - m₁ a

car 2

            T₁' -T₂ '= m₂' a

            T₁ ’= T₂’- m₂’ a

            T₁ '= (T₂'- m₂ a) + 39 a

            T₁ '= T₁ + 39 0.12

            ΔT₁ = 4.68 N

The tension in each of the coupling bars A, B, and C of the luggage carrier changes as,

Tension is the pulling force carried by the flexible mediums like ropes, cables and string.

Tension in a body due to the weight of the hanging body is the net force acting on the body.

At an airport, luggage is unloaded from a plane into the three cars of a luggage carrier, as the drawing shows. The acceleration of the carrier is 0.12 m/s², and friction is negligible.

The acceleration is the same, Tension due to the horizontal component of the forces for car 1, 2 and 3 can be given as,

[tex]\sum F_{1h}=T_A-T_B=m_1a\\\sum F_{2h}=T_B-T_C=m_2a\\\sum F_{3h}=T_C=m_3a[/tex]

On solving the above 3 equation, we get the values of tension in each bar as,

[tex]T_A=(m_1+m_2+m_3)a\\T_B=(m_3+m_2)a\\T_C=m_3a[/tex]

The tension is A and C does not change for this case. The acceleration of the carrier is 0.12 m/s². Thus, the change in tension is B is,

[tex]\Delta T_B=39\times0.12\\\Delta T_B=4.68\rm \;N[/tex]

The tension is A and B does not change for this case. The acceleration of the carrier is 0.12 m/s². Thus, the change in tension is B is,

[tex]\Delta T_C=39\times0.12\\\Delta T_C=4.68\rm \;N[/tex]

Hence, the tension in each of the coupling bars A, B, and C of the luggage carrier changes as,

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The time period of the spring is 2[tex]\pi[/tex][√(m/k)].

The spring constant of a spring is defined as the measurement of ratio of the force that is exerted on the spring to the displacement caused by it.

Here,

The mass of the block = m

Let F be the applied force on the spring and k be the spring constant.

When the mass attached to the spring is pulled to one side then released, it executes SHM.

Therefore we can write that, the applied force,

F = kx

Restoring force = -kx

According to Newton's law, we know that,

F = ma

So,

ma = -kx

Therefore, the acceleration,

a = (-k/m) x

For an SHM, the acceleration is given as,

a = -ω²x

Therefore, we can write that,

-ω²x = (-k/m) x

ω² = k/m

So, the time period of the spring,

T = 2[tex]\pi[/tex]/ω

T = 2[tex]\pi[/tex][√(m/k)]

Hence,

The time period of the spring is 2[tex]\pi[/tex][√(m/k)].

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Answer:

The pressure is 2505 Pa.  

Explanation:

Height, h = 1.5 m

density of blood, d = 1000 kg/cubic meter

Gravity, g = 1.67 m/s^2

let the pressure is P.  

The pressure due to the fluid is given by

P = h d g

P = 1.5 x 1000 x 1.67

P = 2505 Pa

Answer:

a) [tex] \alpha = 1.28 rad/s^{2} [/tex]  

b) Option ii. The angular acceleration would increase

Explanation:

a) The angular acceleration is given by:

[tex] \omega_{f} = \omega_{0} + \alpha t [/tex]

Where:

[tex] \omega_{f} [/tex]: is the final angular speed = v/r

v: is the tangential speed = 6.35 m/s

r: is the radius = 45.0 cm = 0.45 m

[tex]\omega_{0}[/tex]: is the initial angular speed = 0 (the hoop starts from rest)

t: is the time = 11.0 s

α: is the angular acceleration

Hence, the angular acceleration is:

[tex] \alpha = \frac{\omega}{t} = \frac{v}{r*t} = \frac{6.35 m/s}{0.45 m*11.0 s} = 1.28 rad/s^{2} [/tex]  

b) If the radius were smaller, the angular acceleration would increase since we can see in the equation that the radius is in the denominator ([tex] \alpha = \frac{v}{r*t} [/tex]).

Therefore, the correct option is ii. The angular acceleration would increase.

I hope it helps you!  

Answer:

1140 J, 6840 J, 10260 J

Explanation:

Lo x 2 Lo x 3 Lo, Lo = 0.2 m,  K = 150 J/(s · m · C˚) , T = 35 ˚C, T' = 16 ˚C,

time, t = 6 s

The heat conducted is

[tex]H = \frac{K A (T - T') t}{d}\\\\H = \frac{150\times 3\times 0.2\times 0.2\times (35-16) \times 6}{3\times 0.2}\\\\H = 1140 J[/tex]

The heat conducted is

[tex]H = \frac{K A (T - T') t}{d}\\\\H = \frac{150\times 3\times 0.2\times 2\times0.2\times (35-16) \times 6}{3\times 0.2}\\\\H = 6840 J[/tex]

The heat conducted is

[tex]H = \frac{K A (T - T') t}{d}\\\\H = \frac{150\times 3\times 0.2\times 2\times0.2\times (35-16) \times 6}{2\times 0.2}\\\\H = 10260 J[/tex]

Answer:

[tex]\lambda=6.83\times 10^{-5}\ m[/tex]

Explanation:

Given that,

An infrared telescope is tuned to detect infrared radiation with a frequency of 4.39 THz.

We know that,

1 THz = 10¹² Hz

So,

f = 4.39 × 10¹² Hz

We need to find the wavelength of the infrared radiation.

We know that,

[tex]\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{4.39\times 10^{12}}\\\\=6.83\times 10^{-5}\ m[/tex]

So, the wavelength of the infrared radiation is [tex]6.83\times 10^{-5}\ m[/tex].

Answer:

P = 29.3 W

Explanation:

The magnetic field in a solenoid is

          B = μ₀  n i

          i = B /μ₀ n

where n is the density of turns

We can use a direct rule of proportions or rule of three to find the number of turns, 1 a turn has a diameter of 0.100 cm = 10⁻³ m, in the length of

L= 85.1 cm = 0.851 m how many turns there are

         #_threads = 0.851 / 10⁻³

         #_threads = 8.50 10³ turns

the density of turns is

          n = # _threads / L

          n = 8.51 103 / 0.851

          n = 104 turn / m

the current that must pass through the solenoid is

          i = 8.90 10-3 / 4pi 10-7 104

          i = 0.70823 A

now let's find the resistance of the copper wire

         R = ρ L / A

the resistivity of copper is ρ = 1.72 10⁻⁸ Ω m

wire area

         A = π r²

         A = π (5 10⁻⁴)

         A = 7,854 10⁻⁷ m²

let's find the length of wire to build the coil, the length of a turn is

         Lo = 2π r = ππ d

         Lo = π 0.100

         Lo = 0.314159 m / turn

With a direct proportion rule we find the length of the wire to construct the 8.5 103 turns

          L = Lo #_threads

          L = 0.314159 8.50 10³

          L = 2.67 10³ m

resistance is

         R = 1.72 10⁻⁸ 2.67 10₃ / 7.854 10⁻⁷

         R = 5,847 10¹

         R = 58.47 ohm

The power to be supplied to the coil is

          P = VI = R i²

          P = 58.47 0.70823²

          P = 29.3 W

Answer:

9.25 m/s

Explanation:

Answer:

7.8% of the original volume.

Explanation:

From the given information:

Temperature [tex]T_1[/tex] = 22° C = 273 + 22 = 295° C

Pressure [tex]P_1[/tex] = 240 kPa

Temperature [tex]T_2[/tex] = 45° C

At initial temperature and pressure:

Using the ideal gas equation:

[tex]P_1V_1 =nRT_1[/tex]

making V_1 (initial volume) the subject:

[tex]V_1 = \dfrac{nRT_1}{P_1}[/tex]

[tex]V_1 = \dfrac{nR*295}{240}[/tex]

Provided the pressure maintained its rate at 240 kPa, when the temperature reached 45° C, then:

the final volume [tex]V_2[/tex] can be computed as:

[tex]V_2 = \dfrac{nR*318}{240}[/tex]

Now, the change in the volume ΔV =  V₂ - V₁

[tex]\Delta V = \dfrac{nR*318}{240}- \dfrac{nR*295}{240}[/tex]

[tex]\Delta V = \dfrac{23nR}{240}[/tex]

∴

The required fraction of the volume of air to keep up the pressure at (240) kPa can be computed as:

[tex]= \dfrac{\dfrac{23nR}{240}}{ \dfrac{295nR}{240}}[/tex]

[tex]= {\dfrac{23nR}{240}} \times { \dfrac{240}{295nR}}[/tex]

[tex]= 0.078[/tex]

= 7.8% of the original volume.

Explanation:

Given that,

Amplitude, A = 2.5 nm

Wavelength,[tex]\lambda=1.8\ m[/tex]

The speed of the wave, v = 36 m/s

At time t = 0 the left end of the string has its maximum upward displacement.

(a) Let f is the frequency. So,

[tex]f=\dfrac{v}{\lambda}\\\\f=\dfrac{36}{1.8}\\\\f=20\ Hz[/tex]

(b) Angular frequency of the wave,

[tex]\omega=2\pi f\\\\=2\pi \times 20\\\\=125.7\ rad/s[/tex]

(c) The wave number of the wave[tex]=\dfrac{1}{\lambda}[/tex]

[tex]=\dfrac{1}{1.8}\\\\=0.56\ m^{-1}[/tex]

Answer:

The voltage across 150 ohm resistor is 6 volts.

Explanation:

Given that,

Resistors having resistances 150 ohms and 300 ohms are in series. Their equivalent is :

R = 150 + 300

R = 450 ohms

Let I is the current in the circuit. Using Ohm's law,

V = IR

[tex]I=\dfrac{V}{R}\\\\I=\dfrac{18}{450}\\\\I=0.04\ A[/tex]

The current in series remains the same while potential divides. So,

[tex]V_1=IR_1\\\\V_1=0.04\times 150\\\\=6\ V[/tex]

So, the voltage across 150 ohm resistor is 6 volts.