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3 years ago

The total energy of a 0.050 kg object travelling at 0.70 c is:

Physics

2 answers:

Elena L [17]3 years ago

8 0

Answer:

1.1025×10^15Joules

No correct option

Explanation:

The type of energy possessed by the object is kinetic energy. Kinetic energy is the energy due to virtue of an object motion.

KE = 1/2MV² where;

M is the mass of the car = 0.05kg

V is the velocity of the car

Since the car is traveling at 0.7c (c is the speed of light)

speed = 0.7c { 0.7(3×10^8)}

Speed = 2.1×10^8

Substituting this values in the formula given we have;

KE = 1/2×0.05×(2.1×10^8)²

KE = 1.1025×10^15Joules

No correct option.

finlep [7]3 years ago

3 0

What is the unit c denotes here

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C, Since binary ionic compound is only of 2 elements. Mg is ionic and so i F so thats it. H20 is covalent B is more than 1 element, D looks dodgy, nah its dat ionic compunds wouldnt form big ones like SF (6)

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3 years ago

Read 2 more answers

At a rock concert, the sound intensity 1.0 m in front of the bank of loudspeakers is 0.10 W/m². A fan is 30 m from the loudspeak

Klio2033 [76]

To solve this problem we will apply the concepts related to the Area, the power and the proportionality relationships between intensity and distance.

The expression for sound power is,

$P = AI$

Here,

A = Area

I = Intensity

P = Power

At the same time the area can be written as,

$A = \frac{\pi d^2}{4}$

Now the intensity is inversely proportional to the square of the distance from the source, then

$I \propto \frac{1}{r^2}$

The expression for the intensity at different distance is

$\frac{I_1}{I_2}= \frac{r^2_2}{r_1^2}$

Here,

$I_1$ = Intensity at distance 1

$I_2$ = Intensity at distance 2

$r_1$ = Distance 1 from light source

$r_2$ = Distance 2 from the light source

If we rearrange the expression to find the intensity at second position we have,

$I_2 = I_1 (\frac{r_1^2}{r_2^2})$

If we replace with our values at this equation we have,

$I_2 = (0.10W/m^2)(\frac{1.0m^2}{30.0m^2})$

$I_2 = 1.11*10^{-4} W/m^2$

Now using the equation to find the area we have that

$A = \frac{\pi (8.4*10^{-3}m)^2}{4}$

$A = 5.5*10^{-5}m^2$

Finally with the intensity and the area we can find the sound power, which is

$P = AI$

$P = (5.5*10^{-5}m^2)(1.11*10^{-4}W/m^2)$

$P = 6.1*10^{-9}J/s$

Power is defined as the quantity of Energy per second, then

$E = 6.1*10^{-9}J$

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3 years ago

A child drops a ball from a window.The ball strikes the ground in 3.0 seconds.What is the velocity of the ball the instant befor

lord [1]

It might be 4.0 or 2.22344 seconds as velocity speed

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3 years ago

Tensile stress is: A. the strain per unit length. B. the ratio of elastic modulus to strain. C. the ratio of the change in lengt

victus00 [196]

Answer:

D. the same as force. the applied force per cross-sectional area.

Explanation:

Tensile stress of a material is defined as the ratio of the applied force on the material to its cross sectional area. this is expressed mathematically as;

Tensile stress = Force/cross sectional area

Tensile stress = F/A

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6 0

3 years ago

Suppose Mary would like to design an emergency overheating alarm using one of these materials. In her design, at room temperatur

Reptile [31]

Answer:

A. 92.88 °C

B. 401.535 °C

Explanation:

So, the overheating system is going to be based on the principle of thermal linear expansion. The behavior of this principle is ruled by the equation:

∆L= L_i * ∆T * α

Where α is a coefficient of linear expansion. For a cylinder made from polycarbonate α = 70,2*10^(-6) °C^(-1) and for a cylinder made from cast iron α = 12*10^(-6) °C^(-1). If we isolate the term of the temperature’s difference, we have:

∆L/(L_i * α) = ∆T → T_f = T_i + ∆L/(L_i * α)

Replacing the values, for the case of the Polycarbonate we have:

T_f = T_i + ∆L/(L_i * α) = 23°C+0,0273cm/(6,01cm *70,2 * 10^(-6)°C^(-1) ) = 92,88 °C

Replacing the values, for the case of the Cast Iron we have:

T_f = T_i +∆L/(L_i * α) = 23°C + 0,0273cm/(6,01cm * 12 * 10^(-6) °C^(-1) ) = 401,535 °C

As we see, is way better to use the polycarbonate in this application.

Have a nice day. Let me know if I can help you with anything else. :D

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3 years ago