How many wavelengths of a wave pass a point if the frequency of the wave is 4 hertz?

Which of the following is a risk of obesity?

Kruka [31]

What are the multiple choice answers?

6 0

3 years ago

If in the experiment, m1 is 38 g, m2 is 63 g, and m3 is 58 g, "and m3 remains static, what is the tension in the string connecti

melomori [17]

Let's call a the acceleration of the system. The problem says that the block m3 is static, so the acceleration is zero: a=0.
Calling $T_1$ the tension of the string between m1 and m3, and $T_2$ the tension of the string between m2 and m3, the problem can be solved by writing the following system of equations:
$m_1 g-T_1=m1_a$
$T_1-T_2=m_3 a$
$T_2-m_2g=m_2a$
However, we know that a=0 and the problem asks only for $T_1$ , so we just need to solve the first equation:
$m_1 g -T_1 =0$
and so
$T_1=m_1g=0.038~kg \cdot 9.81~m/s^2 = 0.37~N$

7 0

3 years ago

Waves must exhibit a constant phase difference for interference to occur. Please select the best answer from the choices provide

zalisa [80]

True is what it is/ ,,,,,,,,,,,,,

8 0

3 years ago

A 200 kg weather rocket is loaded with 100 kg of fuel and fired straight up. It accelerates upward at 30 m/s2 for 35 s , then ru

Gre4nikov [31]

Answer:

a) $h_m=74625\ m$

b) $t=265.55\ s$

Explanation:

Given:

mass of rocket, $m_r=200\ kg$

mass of fuel, $m_f=100\ kg$

acceleration of the rocket consuming fuel, $a=30\ m.s^{-2}$

time after which the fuel exhaust, $t_f=35\ s$

During the phase of fuel exhaustion:

velocity attained by the rocket just as the fuel ends:

$v_f=u+a.t_f$

where:

$u=$ initial velocity of the rocket = 0

$v_f=0+30\times 35$

$v_f=1050\ m.s^{-1}$ this will be the initial velocity for the phase of ascending of the rocket's height under the influence of gravity.

height at which the fuel finishes:

$v_f^2=u^2+2a.h_f$

$1050^2=0^2+2\times 30\times h_f$

$h_f=18375\ m$

During the phase of ascend in height of rocket after the fuel is over:

Time taken to reach the top height after the fuel is over:

$v=v_f+g.t'$

at top v = (final velocity during this course of motion )= 0 $m.s^{-1}$

$0=1050-9.8\times t'$

$t'=107.1429\ s$

Height ascended by the rocket after the fuel is over:

$v^2=v_f^2+2g.h'$

at the top height the velocity is zero

$0^2=1050^2-2\times 9.8\times h'$ (-ve sign denotes that the direction of motion is opposite to that of acceleration)

$h'=56250\ m$

Therefore the maximum altitude attained by the rocket:

$h_m=h_f+h'$

$h_m=18375+56250$

$h_m=74625\ m$

b)

time taken by the rocket to fall back to the earth:

$h_m=v.t_m+\frac{1}{2} g.t_m^2$

where:

$v=$ initial velocity of the rocket during the course of free fall from the top height.

$74625=0+4.9\times t_m^2$

$t_m=123.41\ s$

Now the total time for which the rocket is in the air:

$t=t_f+t'+t_m$

$t=35+107.1429+123.41$

$t=265.55\ s$

4 0

3 years ago

a) When we were examining the Electromagnetic Tab, we saw that a flow of electrons or a current as we say it, creates a magnetic

olga nikolaevna [1]

Answer:

Magnetic field can be used to produce current, infact a changing magnetic field can produce current.

A changing magnetic field in a loop causes the flux linked with the loop to change in turn generating a emf in the loop and therefore a current.

For a loop of area A and resistance R.

I =dPhi/dt/R

В. А

I = AcosФ/R .dB /dt

But it isn't reasonable to say that we can create a magnetic field by having a flow of current and this can be used to make more current because the current generated due to change in magnetic field created by increase/decrease in flow of current will be in a direction such that it will counter act the change in magnetic field caused by increase/decrease in current flow.(lenz's law).

We were unable to transcribe this image

Ф= В. А

I = Acos dB Rd

3 0

3 years ago