32. Which sub-atomic particle has a charge of +1?

If two firecrackers produce a sound level 85dB. What level does the explosion of one firecracker produce?

mars1129 [50]

Level of sound is related to intensity by this equation

$L = 10 Log \frac{I}{I_o}$

given that

L = 85 dB

also we know that

$I_o = 10^{-12} W/m^2$

now we have

$85 = 10 Log \frac{I}{10^{-12}}$

By solving above equation

$I = 10^{8.5} * 10^{-12}$

$I = 3.16 * 10^{-4} W/m^2$

now above is the intensity due to two firecrackers and if we wish to find the sound level of one firecracker then we will find its half level intensity

$I_1 = \frac{I}{2}$

$I_1 = 1.58 * 10^{-4}$

now again by above formula

$L = 10 Log \frac{1.58 * 10^{-4}}{10^{-12}}$

$L = 82 dB$

8 0

3 years ago

Would u rather/ have a penny that duplicates its self every day or win 1 million dollars once

arlik [135]

Answer:

1 million dollars once

Explanation:

Well, both would be nice. In total, you will get more from the million dollars because it takes over 2,739 years to get 1 million dollars worth of pennies.(if you get 1 a day that is)

8 0

3 years ago

Why does a pencil in a glass container filled with water appear to be bent?

Bogdan [553]

The phenomenon is called "refraction". It's the process of
light waves bending toward a different direction when they
cross a boundary between different media ... in this case,
from water into air.

Your brain doesn't know that the light waves bent toward a
new direction when they came out of the water into the air,
so your brain locates the bottom half of the pencil just like it
ALWAYS does ... in the direction the light waves are coming FROM.

4 0

4 years ago

Read 2 more answers

Struggling with this. Can you help?

pishuonlain [190]

Answer:

Unclear without more information

Explanation:

This is about transfer of energy. If you assume there is no energy lost to the environment (virtually impossible) - then all of the potential energy at the beginning would be transferred to kinetic energy along the route.

So, assuming that the rollercoaster has a velocity of 0 m/s at point A, then you can calculate the potential energy using: $Ep =mgh_A$

At the point D, you would assume that the energy is split between some kinetic energy and some potential energy. So, we could say that the total energy is the sum of these: $Etot=Ep+Ek=mgh_{D} +\frac{mv^2}{2}$

If we assume all energy is transferred (ie. no energy lost to friction/heat etc) then we can equate these two and solve:

$mgh_A=mgh_{D} +\frac{mv^2}{2}\\\\h_D=\frac{(2gh_A-v^2)}{2g} =22.4$

However, this answer seems unlikely given the drawing - which implies that there is perhaps more information that is missing??

6 0

3 years ago

Assuming the same initial conditions as described in FNT 2.2.1-1, use the energy-interaction model in two different ways (parts

Alenkinab [10]

Answer:

(a). Vf = 7.14 m/s

(b). Vf = 7.14 m/s

(c). same answer

Explanation:

for question (a), we would be applying conservation of energy principle.

but the initial height is h = 1.5 m

and the initial upward velocity of the ball is Vi = 10 m/s

Therefore

(a). using conservation law

Ef = Ei

where Ef = 1/2mVf² + mghf ........................(1)

also Ei = 1/2mVi² + mghi ........................(2)

equating both we have

1/2mVf² + mghf = 1/2mVi² + mghi

eliminating same terms gives,

Vf = √(Vi² + 2g (hi -hf))

Vf = √(10² + -2*9.8*2.5) = 7.14 m/s

Vf = 7.14 m/s

(b). Same process as done in previous;

Ef = Ei

but here the Ef = mghf ...........(3)

and Ei = 1/2mVi² + mghi ...........(4)

solving for the final height (hf) we relate both equation 3 and 4 to give

mghf = 1/2mVi² + mghi ..............(5)

canceling out same terms

hf = hi + Vi²/2g

hf = 1.5 + 10²/2*9.8 = 6.60204m ............(6)

recalling conservation energy,

Ef = Ei

1/2mVf² + mghf = mghi

inputting values of hf and hi we have

Vf = √(2g(hi -hf)) = 7.14 m/s

Vf = 7.14 m/s

(c). From answer in option a and c, we can see there were no changes in the answers.

4 0

4 years ago