One reason the skeletal system is important is because ?

If a FM radio station broadcasts at 80. 3 MHz (megahertz), what is its wavelength in m (speed of light 3. 0 x 108 m/s)

hammer [34]

Answer:

Wavelength = 3.74 m

Explanation:

In order to find wavelength in "metres", we must first convert megahertz to hertz.

1 MHz = 1 × 10⁶ Hz

80.3 Mhz = <em>x</em>

<em>x </em>= 80.3 × 1 × 10⁶ = 8.03 × 10⁷ Hz

The formula between wave speed, frequency and wavelength is:

v = fλ [where v is wave speed, f is frequency and λ is wavelength]

Reorganise the equation and make λ the subject.

λ = v ÷ f

λ = (3 × 10⁸) ÷ (8.03 × 10⁷)

λ = 3.74 m [rounded to 3 significant figures]

8 0

3 years ago

Describe different types of motion with examples. (4)

Illusion [34]

Answer:

a)

there r two types of motion, uniform and non-uniform

uniform means equal distance travelled at equal intervals of time

and non-uniform is exactly the opposite.

b)

quantities which can be represented by magnitude along r called scalar quantities such as speed.

quantities which need magnitude along with direction r called vector quantities such as velocity.

c)

velocity=10m/s

acceleration = u-v/s i.e initial final velocity - initial velocity upon time

acceleration= 0.2m/s sq

time= 30s

10 = displacement/time

10 = x/30

10 = 300

Answer is 300 meters - distance/displacement.

8 0

3 years ago

Read 2 more answers

A thin, rectangular sheet of metal has mass M and sides of length a and b. Find the moment of inertia of this sheet about an axi

Lubov Fominskaja [6]

Answer:

The moment of inertia is $I=\frac{M}{12} a^{2}$

Explanation:

The moment of inertia is equal:

$I=\int\limits^a_b {r^{2} } \, dm$

If r is $-\frac{a}{2}$

and $dm=\frac{M}{a} dr$

$I=\int\limits^a_b {r^{2}\frac{M}{a} } \, dr\\a=\frac{a}{2} \\b=-\frac{a}{2}$

$I=\frac{M}{a} \int\limits^a_b {r^{2} } \, dr\\\\I=\frac{M}{a} (\frac{M}{3} )_{b}^{a}\\ I=\frac{M}{3a} (\frac{a^{3} }{8} +\frac{a^{3} }{8} )\\I=\frac{M}{12} a^{2}$

7 0

4 years ago

A machine exerts a 100 N force to the right over a 5.00 meter length in 4.00 seconds. Calculate the power output of this machine

bixtya [17]

125 W is the power output of this machine.

Answer:

Explanation:

Power is defined as the amount of work done on the system to move that system from its original state within the given time interval. So it can be determined by the ratio of work done with time interval. As work done is the measure of force required to move a system to a certain distance. Work done is calculated as product of force with displacement.

So in the present case, the force is given as 100 N, the displacement is given as 5 m and the time is given as 4 s, then power is

$Power = \frac{Work done}{Time}$

As Work done = Force acting on the machine × Displacement

So $Power = \frac{(Force * Displacement)}{Time}$

Power = $\frac{(100*5)}{4}$ =125 W

So, 125 W is the power output of this machine.

6 0

3 years ago

Ezra (m = 20.0 kg) has a tire swing and wants to swing as high as possible. He thinks that his best option is to run as fast as

Dmitriy789 [7]

Answer:

a) $v=5.6725\,m.s^{-1}$

b) $h= 1.6420\,m$

Explanation:

Given:

mass of the body, $M=20\,kg$

mass of the tyre, $m=10\,kg$

length of hanging of tyre, $l=3.5m$

distance run by the body, $d=10m$

acceleration of the body, $a=3.62m.s^{-2}$

(a)

Using the equation of motion :

$v^2=u^2+2a.d$ ..............................(1)

where:

v=final velocity of the body

u=initial velocity of the body

here, since the body starts from rest state:

$u=0m.s^{-1}$

putting the values in eq. (1)

$v^2=0^2+2\times 3.62 \times 10$

$v=8.5088\,m.s^{-1}$

Now, the momentum of the body just before the jump onto the tyre will be:

$p=M.v$

$p=20\times 8.5088$

$p=170.1764\,kg.m.s^{-1}$

Now using the conservation on momentum, the momentum just before climbing on the tyre will be equal to the momentum just after climbing on it.

$(M+m)\times v'=p$

$(20+10)\times v'=170.1764$

$v'=5.6725\,m.s^{-1}$

(b)

Now, from the case of a swinging pendulum we know that the kinetic energy which is maximum at the vertical position of the pendulum gets completely converted into the potential energy at the maximum height.

So,

$\frac{1}{2} (M+m).v'^2=(M+m).g.h$

$\frac{1}{2} (20+10)\times 5.6725^2=(20+10)\times 9.8\times h$

$h\approx 1.6420\,m$

above the normal hanging position.

3 0

3 years ago