What is the mass m of the elevator? use g=10m/s2 for the magnitude of the acceleration of gravity.

A large crate with mass m rests on a horizontal floor. The static and kinetic coefficients of friction between the crate and the

____ [38]

Answer:

Explanation:

Check attachment for solution

6 0

3 years ago

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

Margarita [4]

Answer:

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

Explanation:

We have to make a hollow sphere of inner radius $r_1$ and outer radius $r_2$ .

Then the mass of the material required to make such a sphere would be calculated as:

Total volume of the spherical shell:

$V_t=\frac{4}{3} \pi.r_2^3$

And the volume of the hollow space in the sphere:

$V_h=\frac{4}{3} \pi.r_1^3$

Therefore the net volume of material required to make the sphere:

$V=V_t-V_h$

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

Now let the density of the of the material be $\rho$ .

Then the mass of the material used is:

$m=\rho.V$

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

4 0

4 years ago

The Coriolis effect causes prevailing winds in the continental United States to blow toward the ________.

jonny [76]

I think its B because it never has a the turn over to any other side except for the west.

5 0

3 years ago

While riding a multispeed bicycle, the rider can select the radius of the rear sprocket that is fixed to the rear axle. The fron

gtnhenbr [62]

Answer:

2.9 cm

Explanation:

Assuming that the rear wheel has a radius of 0.330 m

Given that

r(a) = 12 cm -> 0.12 m

w(a) = 0.6 rev/s -> 3.77 rad/s

v = 5 m/s

r(w) = 0.330 m

The speed on any point on the rim at the sprocket in the front is

v(a) = w(a).r(a) = 3.77 * 0.12 = 0.4524 m/s

Also,

v(a) = speed at any point on the chain

v(b) = speed at any point on the rim of the rear sprocket

v(a) = v(b)

where v(b) = w(b).r(b)

Recall that the speed at any point on the rear wheel is v, where

v = w(b).r(w)

5 = w(b) * 0.330

w(b) = 5/0.330

w(b) = 15.15 rad/s

On substituting this in the equation, we have

v(b) = w(b).r(b).

Remember also, that v(a) = v(b), so

0.4524 = 15.15 * r(b)

r(b) = 0.4524 / 15.15

r(b) = 0.029 m -> 2.9 cm

Therefore, the radius of the rear sprocket needed is 2.9 cm

7 0

3 years ago

Suppose you're on a hot air balloon ride, carrying a buzzer that emits a sound of frequency f. If you accidentally drop the buzz

Olin [163]

Answer:

The correct answer is option 'd': The frequency decreases and the intensity of the sound decreases.

Explanation:

1) Effect on Frequency

According to Doppler's effect of sound we have

for a source of sound moving away from the observer the relation between the observed and the original frequency is given by

$f_{app}=\frac{c-v_{rec}}{c+v_{s}}\times f_{original}$

where

c = speed of sound in air

$v_{rec}$ is the velocity of observer of sound

$v_{s}$ is the velocity of source of sound

$f_{o}$ is the original frequency of sound

As we see the ratio is less than 1 thus the frequency of sound that the observer receives is less than that of source.

2) Effect on Intensity:

At a distance 'r' from source emitting a wave of Power 'P' is given by

$I=\frac{P}{4\pi r^{2}}$

As we see on increasing 'r' intensity of sound decreases.

3 0

4 years ago