A scientist studies how air blowing on plants affects their growth. He uses fans to create different amounts of wind and measures the growth of the plants. What would make this experiment more repeatable?

Answer:

Explanation:

It's not equal and opposite. You're thinking of Newton's 3rd Law. This is not that. This is gravitational attraction between 2 objects. We can figure out mathematically the pull that the earth has on a single person, by using the equation for gravitational force and the universal gravitational constant, G:

[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] where G is the universal gravitational constant, m1 is the mass of one person, m2 is the mass of the earth, and r-squared is the addition of the radius of the earth plus the radius of you in relation to the surface of the earth.

Let's say a person weighs 150 pounds; in Newtons this is 667 N (rounded from 667.233); his mass then, in terms of the metric system (using 9.8 for gravity), is 68.2 kg. Let's also say that this person is 6 feet tall. 6 feet is the same as 1.83 m (rounded to 3 sig fig's) and the radius from that person's center to the surface of the earth would be about half that height at r = .915 meters. Filling in the formula:

[tex]F_g=\frac{(6.67*10^{-11})(68.2)(5.98*10^{24})}{(6.38*10^6)^2}[/tex] it turns out that the person's radius adds nothing significantly to the radius of the earth, so it doesn't even count mathematically. It's way too small compared to the earth's radius (which is the denominator of that equation). We find that

[tex]F_g=668N[/tex] That's the pull that the earth has on that person which, not coincidentally, is the weight in pounds we said that the person was. Isn't physics amazing!?

We know

[tex]\boxed{\sf Power=\dfrac{Work\:done}{Time}}[/tex]

[tex]\\ \sf\longmapsto Power=\dfrac{Force\times displacement}{Time}[/tex]

[tex]\\ \sf\longmapsto Power=\dfrac{50\times 10}{10}[/tex]

[tex]\\ \sf\longmapsto Power=\dfrac{500}{10}[/tex]

[tex]\\ \sf\longmapsto Power=50W[/tex]

If A = i - j + k, then the magnitude of A is

||A|| = √(1² + (-1)² + 1²) = √3

Then the unit vector in the direction of A is 1/||A|| multiplied by A :

u = A/||A|| = (i - j + k)/√3

(choice D)

Answer:

Zero because the applied force is perpendicular to the motion of the object.

No work is done on an object moving is a circular path about a central attractive force.

Any work done in such a case would result in a change in the orbit.

The reaction force must be:

75 N up

Answer:

hey I am in class 6 why did you ask

Answer:

E_O = 96J

Explanation:

E_O = E_I*(%e/100%)

E_O = 120J*(80%/100%)

E_O = 96J

Answer:

[tex]{ \bf{false}}[/tex]

Explanation:

Because it breaks the law of moments.

Answer:

add text fully or atleast add book name edition . solution is in picture.  chk pictures ignore b part

Explanation:

Explanation:

st system:the internationak system of measurement which i declared form internationäl convention of scientists held in france in 1960AD is Si system

CGS System:it measure in length in centimeter mass in gram time in second

Answer:

The MKS (metre, kilogram, second) system of units is the fundamental core of the SI (Systeme Internationale, or International System) of measurement. As various fields grow new forms of measurements based on MKS, terms or exact definitions may vary in different scientific or engineering disciplines. These inconsistencies are sorted out by the international committee that defines the SI system of units and keeps it up to date.

So the MKS is the static core, and the SI is the evolving, growing system of metric measurement.

Metres and kilograms were introduced after the French Revolution around 1790. Seconds were added by the 1830s, building the MKS system. More units came later. By 1948, a need was seen to develop a clear and consistent set of terms for measurement, and this led to 12 years of work, ending with the release of the first version of the SI in 1960.

The SI now has seven base units of measure. It begins with the original three metre, kilogram, and second, and adds the ampere for electricity, candela for light, kelvin for temperature, and mole for amount (number of atoms or molecules) of a substance.

The SI defines how each fundamental unit can be measured or obtained experimentally. These definitions have changed over time. For example, the metre was originally a measure related to the circumference of the Earth, then a set number of waves of a particular wavelength, and now a distance traveled by light in a vacuum in a certain period of time.

The SI also defines modifying terms such as milli-, centi-, and kilo- that are a specific number of each unit.

The SI includes many other derived units, as well.

By standardizing international use of measurements across different fields of science and engineering, the SI reduces confusion that would slow scientific progress and error that can produce engineering catastrophe such as the loss of the Mars Climate Orbiter in 1999 due to a table that should have been in metric units (kilograms and meters) being provided in United States customary units (pounds and inches).*

The Mars Climate Orbiter and its mission were lost due to a failure to use SI units consistently.

Hope this help you!:)

C) 2N/M

The formula is F=ke

where F = force,k= spring constant and e=elasticity

2=k*1

k=(2/1)

k=2N/M

We know

[tex]\boxed{\sf Spring\:constant(k)=\dfrac{F}{x}}[/tex]

[tex]\\ \sf\longmapsto k=\dfrac{2}{1}[/tex]

[tex]\\ \sf\longmapsto k=2N/m[/tex]

Answer:

Ke²

Explanation:

So,

q1 = e

q2 = e

r = 1m

By coulumb's law,

F = K (q1q2/r²)

F = K (e)(e)/(1)²  

F = Ke²  

Option(a)

Answer:

3 m/s

Explanation:

Given,

Total distance = 60 m

Total time = 20 s

We know that,

Average speed = Total distance/Total time

=> Average speed = 60 m/20 s

=> Average speed = 3 m/1 s

=> Average speed = 3 m/s

Average speed=Total distance/Total time

[tex]\\ \sf\longmapsto Average\:Speed=\dfrac{60}{20}[/tex]

[tex]\\ \sf\longmapsto Average\:Speed=3m/s[/tex]

Explanation:

Convert the time to seconds : 5minutes × 60 = 300seconds

Acceleration = Velocity / Time

Acceleration = 20m/s / 300s

Acceleration = 0.067m/s²

Distance = Velocity × Time

Distance = 20m/s × 300seconds

Distance = 6000m

Answer:

Explanation:

S.No Concave                      Mirror  Convex Mirror  

1.  Dentist's mirror               Rear view mirror of vehicles  

2.  Shaving Mirror                Streetlights  

3.  Headlight of vehicles      Water glass surface  

4.   Caving side of spoon     Curving side of spoon

5.   Torch glass                    Electric Bulb  

6.  Inner surface of              Outer surface of steel basin  

steel basin  

7.  Lunch plates                   Calling bell

8.  Microscope                       Optical instruments  

9.   Satellite dishes              Fish eye lenses

Answer:

Explanation:

The series three. The series 3 will cut the voltage into 1/3. The current will also be lower because of the voltage drop.

The parallel circuit will not cut the voltage and the current will be tripled because each bulb is taking out exactly what it needs.

As an aside, house wiring would be a nightmare if the bulbs were connected in series. If one bulb burned out, you'd have to find it in the dark because they all would go out.

Answer:

a bus moving with acceleration of 2 meter per second square

Answer:

It means that it's velocity is 2m/s per s

Means it travels 2m in 1st second and 4m in 2nd sec

Answer:

b. the seasons

Explanation:

Answer:

Explanation:

The unit of power is watt .

Answer:

15

Explanation:

muntiply the 5.0.3.0 ,you will get ans

It's the velocity, but only the magnitude. It can't show the direction of the velocity. So it's better to call it speed.

Answer: I hope this helps you

Explanation:

Answer:

B. Rubidium has more protons and more electrons than calcium.

Explanation:

Answer:

REENA IS STRONGER

Explanation:

so let's just find how long each person takes to carry the load half way, to proof who is stronger.

Rahul takes 5 minutes

5/2

= 2.5

so Rahul takes 2.5 minutes to travel 100 metres with 80 kg

where as

Reena take 4 minutes

4/2

= 2

so Reena takes 2 minutes to travel 100 metres with 80 kg

__________________________________________________

Therefore Reena is stronger because, she went 30 seconds before Rahul

Answer:

hope it helps you

Explanation:

fonot judge through bad handwriting :(

The option There is a warm layer of air and a cold layer of air closer to the ground. is the correct answer