What is better for measuring how hard you are actually working, Target Heart Rate or Rating of perceived exertion?

Which scientist determined that the further a planet is from the sun, the longer it takes to orbit the sun? ~ I think it might b

lozanna [386]

That was Johannes Kepler.

He couldn't say why that should happen. But he was able to show that
if we assume the the sun is in the center of the solar system, and assume
that the planets revolve around the sun in elliptical orbits, and assume that
the farther a planet is from the sun the longer it takes to orbit the sun, then
that matches everything that we see the planets actually doing in the sky.

Then Isaac Newton came along, and wrote down a short, simple formula
for the force of gravity. And then he showed that IF his formula for gravity
is correct, then the planets MUST do everything that we see them actually
doing in the sky, and they MUST behave according to Kepler's laws.

Wotta guy !

7 0

3 years ago

A resonant circuit using a 286-nFnF capacitor is to resonate at 18.0 kHzkHz. The air-core inductor is to be a solenoid with clos

lukranit [14]

Answer:

The inductor contains $N = 523962.32$ loops

Explanation:

From the question we are told that

The capacitance of the capacitor is $C = 286nF = 286 * 10^{-9} \ F$

The resonance frequency is $f = 18.0 kHz = 18*10^{3} Hz$

The diameter is $d = 1.1 mm = \frac{1.1 }{1000} = 0.00011 \ m$

The of the air-core inductor is $l = 12 \ m$

The permeability of free space is $\mu_o = 4 \pi *10^{-7} \ T \cdot m/A$

Generally the inductance of this air-core inductor is mathematically represented as

$L = \frac{\mu_o * N^2 \pi d^2}{4 l}$

This inductance can also be mathematically represented as

$L = \frac{1}{w^2}$

Where $w$ is the angular speed mathematically given as

$w = 2 \pi f$

So

$L = \frac{1}{4 \pi ^2 f^2}$

Now equating the both formulas for inductance

$\frac{\mu_o * N^2 \pi d^2}{4 l} = \frac{1}{4 \pi ^2 f^2}$

making N the subject of the formula

$N = \sqrt{\frac{1}{(2 \pi f)^2} * \frac{4 * l }{\mu_o * \pi d^2 C} }$

$N = \frac{1}{2 \pi f} * \frac{2}{d} * \sqrt{\frac{l}{\pi * \mu_o * C} }$

Substituting value

$N = \frac{1}{ 3.142 * 18*10^{3} * 0.00011 } \sqrt{\frac{12}{ 3.142 * 4 \pi *10^{-7}* 286 *10^{-9}} }$

$N = 523962.32$ loops

4 0

3 years ago

What happens to the current supplied by the battery when you add an identical bulb in parallel to the original bulb?

Marysya12 [62]

Answer:

b. The current stays the same.

Explanation:

In the case given current is supplied by the battery to a bulb . Here, we should know that bulb also apply resistance to the flow of current .

Now, when an identical bulb is connected in parallel to the original bulb .

Therefore, both the resistance( bulb) are in parallel.

We know, when two resistance are in parallel , current through them is same and voltage is divided between them.

Therefore, in this case current stays same in the original bulb.

Hence, this is the required solution.

6 0

4 years ago

A forklift lifts 5 boxes from the ground to a height of 2 meters (m). The boxes push down with a force of 1000 newtons (N). How

Nata [24]

Hello!

Answer:

2000 J

Explanation

Work equation is expressed as:

$W=F.d.Cos \alpha$

Where:

F: Applied force
d: traveled distance
α: Angle between the direction of the force and the direction of the movement. (in this case, both of the direction are the same, so the angle is 0°)

By substituting:

$F=1000N.2m.Cos(0)=2000N.m=2000 J$

Have a nice day!

8 0

3 years ago

In the graph, which two regions show the particle undergoing zero acceleration and negative acceleration respectively?

GuDViN [60]

when velocity and time both are constant and when velocity will decrease the acceleration will be negative

7 0

4 years ago