Physics question? please see photo above

What mass of a material with density ρ is required to make a hollow spherical shell having inner radius r1 and outer radius r2?

krok68 [10]

Answer: $m=\frac {\rho}{\frac{4}{3} \pi( (r_2)^{3} - (r_1)^{3}) }$

It is given that:

Density of material =ρ

radius of inner spherical shell = $r_1$

radius of outer spherical shell= $r_2$

we know that the volume of sphere is $\frac{4}{3}\pi r^{3}$

Volume of the given spherical shell = $\frac{4}{3}\pi( (r_2)^{3}-(r_1)^{3})$

Then mass of the spherical shell can be calculate as:

Mass, m=density/ volume

$m=\frac {\rho}{\frac{4}{3} \pi ((r_2)^{3} - (r_1)^{3}) }$

6 0

3 years ago

Monochromatic light with wavelength 588 nm is incident on a slit with width 0.0351 mm. The distance from the slit to a screen is

Norma-Jean [14]

Answer:

Explanation:

A. Using

Sinစ= y/ L = 0.013/2.7= 0.00481

စ=0.28°

B.here we use

Alpha= πsinစa/lambda

= π x (0.0351)sin(0.28)/588E-9m

= 9.1*10^-2rad

C.we use

I(စ)/Im= (sin alpha/alpha) ²

So

{= (sin0.091/0.091)²

= 3*10^-4

6 0

4 years ago

What is the force of gravitational attraction between an object with a mass of 100 kg and another object that has a mass of 300

Leokris [45]

Answer:

5 x 10⁻⁷N

Explanation:

Given parameters:

Mass of object 1 = 100kg

Mass of object 2 = 300kg

Distance = 2m

Unknown:

Force of gravitational attraction between the objects = ?

Solution:

Newton's law of universal gravitation states that the gravitational force between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

From Newton's law of universal gravitation we derive an expression:

Fg = $\frac{Gm_{1} m_{2} }{r^{2} }$

G is the universal gravitation constant = 6.67 x 10⁻¹¹

m is the mass

r is the distance between the bodies

Now insert the parameters and solve;

Fg = 6.67 x 10⁻¹¹ x $\frac{100 x 300}{2^{2} }$ = 5 x 10⁻⁷N

7 0

3 years ago

Two immersion heaters, A and B, are both connected to a 120.0-V supply. Heater A can raise the temperature of 1.00 L of water fr

Inessa05 [86]

Answer:

Ratio of resistance of heater A to resistance of heater B is 5.80

Explanation:

Consider C be the specific heat of water, R₁ and R₂ be the resistance of heater A and heater B respectively.

Given:

Mass of water in heater A, m₁ = 1 L

Mass of water in heater B, m₂ = 5.80 L

Initial temperature, T₀ = 20 ⁰C

Final temperature, T₁ = 90 ⁰C

Time, t = 5 min

Amount of heat required to raise the temperature of water by heaters A and B are given by:

Q₁ = m₁C(T₁ - T₀) and

Q₂ = m₂C(T₁ - T₀)

Ratio of power used by both the heaters A and B is:

$\frac{P_{1} }{P_{2} } =\frac{Q_{1} }{t} \times\frac{t}{Q_{2} }$

Since, time t, temperature difference(T₁ - T₀) and specific heat C are same for both the heaters A and B. So, the above equation becomes:

$\frac{P_{1} }{P_{2} } =\frac{m_{1} }{m_{2} }$ ...(1)

The relation to determine electrical power for both heaters A and B are:

$P_{1}=\frac{V^{2} }{R_{1} }$ and

$P_{2}=\frac{V^{2} }{R_{2} }$

Here V is the voltage applied to both the heaters and is equal.

So, the ratio of electrical power of heaters is:

$\frac{P_{1} }{P_{2} } =\frac{R_{2} }{R_{1} }$ ....(2)

But according to the problem, the electrical power is converted into the thermal power. So,equation (1) and (2) are equal. Hence,

$\frac{m_{1} }{m_{2} } =\frac{R_{2} }{R_{1} }$

Substitute the suitable values in the above equation.

$\frac{1 }{5.80 } =\frac{R_{2} }{R_{1} }$

$\frac{R_{1} }{R_{2} }=5.80$

6 0

3 years ago

Why is a steam burn more damaging than a burn from boiling water at the same temperature?

maksim [4K]

The phase change (from gas to liquid) that the steam undergoes right when it touches your skin releases a lot of energy right onto your skin so it burns a ton. The boiling water would just burn you until it reaches the same temperature as your skin.

4 0

3 years ago