The SI unit for force is the _________.
A. mass
B. kilogram
C. newton
D. acceleration of gravity
E. weight

We need evidence to be able to continually test theories about the composition and origin of our solar system and galaxies in order to verify the theories and to make laws.

A theory is an explanation for observations of the natural world that has been carried by using the scientific method, and which brings together many facts.

So we can conclude that we need evidence to test theories about the composition and origin of our solar system in order to verify the theories and to make laws.

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[tex]1)\\\\\text{Kinetic energy,}\\\\E_k = \dfrac 12 mv^2 \\\\\implies m = \dfrac{2E_k}{v^2} = \dfrac{2\times 4500}{30^2}=10~ kg\\ \\2)\\\\\text{Kinetic energy,}\\\\E_k = \dfrac 12mv^2 \\\\\implies v^2 = \dfrac{2E_k}m\\\\\implies v = \sqrt{\dfrac{2E_k}{m}}=\sqrt{\dfrac{2 \times 320}{\dfrac{20}{9.8}}}= 17.709 ~ ms^{-1}\\\\3)\\\\\text{Kinetic energy,}\\\\E_k=\dfrac 12 mv^2=\dfrac 12 \times 50 \times 10^2=2500 ~J\\\\\\[/tex]

[tex]4)\\\\\text{Potential energy,}\\\\E_p =mgh = 5\times 9.8\times 1.5 = 73.5 ~J[/tex]

Answer:

approximately 7 seconds

Explanation:

The given scenario is just an example of Projectile Motion.

In this question, we are given:

- Initial Velocity (u) = 40 m/s

- Angle of Elevation (θ) = 60 degrees

- Distance of Bird (s) = 145 meters        [Not used for the time of flight]

Time of Flight:

[tex]T = \frac{2uSin(\theta)}{g}[/tex]

we will use g = 9.8 m/s/s since we are not told otherwise.
[tex]T = \frac{2(40)Sin(60 degrees)}{9.8}[/tex]

[tex]T = \frac{40\sqrt{3}}{9.8}[/tex]

T = 4.081(√3) seconds
rounded to 7 seconds

As it mentioned

So

power is 100W

Now

Current be I

[tex]\\ \rm\rightarrowtail I=\dfrac{P}{V}=\dfrac{100}{120}=\dfrac{5}{6}=0.8A[/tex]

Answer:

0

Explanation:

because no distance covered by body

The electric potential V(z) on the z-axis is :  V = [tex](\frac{Q}{a^2} ) [ (a^2 + z^2)^{\frac{1}{2} } -z[/tex]

The magnitude of the electric field on the z axis is : E = kб 2[tex]\pi[/tex]( 1 - [z / √(z² + a² ) ] )

Given data :

V(z) =2kQ / a²(v(a² + z²) ) -z  

Considering a disk with radius R

Charge = dq

Also the distance from the edge to the point on the z-axis = √ [R² + z²].

The surface charge density of the disk ( б ) = dq / dA

Small element charge dq =  б( 2πR ) dr

dV  [tex]\frac{k.dq}{\sqrt{R^2+z^2} } \\\\= \frac{k(\alpha (2\pi R)dR}{\sqrt{R^2+z^2} }[/tex]  ----- ( 1 )

Integrating equation ( 1 ) over for full radius of a

∫dv = [tex]\int\limits^a_o {\frac{k(\alpha (2\pi R)dR)}{\sqrt{R^2+z^2} } } \,[/tex]

 V = [tex]\pi k\alpha [ (a^2+z^2)^\frac{1}{2} -z ][/tex]

     = [tex]\pi k (\frac{Q}{\pi \alpha ^2})[(a^2 +z^2)^{\frac{1}{2} } -z ][/tex]

Therefore the electric potential V(z) = [tex](\frac{Q}{a^2} ) [ (a^2 + z^2)^{\frac{1}{2} } -z[/tex]

Also

The magnitude of the electric field on the z axis is : E = kб 2[tex]\pi[/tex]( 1 - [z / √(z² + a² ) ] )

Hence we can conclude that the answers to your question are as listed above.

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The initial velocity of a car that accelerates to a speed of 55 m/s within the span of 8 seconds is 23m/s.

The initial velocity of a moving body can be calculated using the following formula:

a = v - u/t

Where;

According to this question, a car accelerates to a speed of 55 m/s within the span of 8 seconds. If its acceleration was 4 m/s², the initial velocity is calculated as follows:

4 = 55 - u/8

32 = 55 - u

u = 55 - 32

u = 23m/s

Therefore, the initial velocity of a car that accelerates to a speed of 55 m/s within the span of 8 seconds is 23m/s.

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Answer: B. Green

Explanation:

        Since the object absorbs all the other options listed here, it will reflect green light. This makes the object appear green to our eyes.

        Blue (A), indigo (C), and red (D) are listed in red, orange, yellow, blue, indigo, and violet. Green is not, so this is our answer.

     Fun fact:

An example of this is grass!

Answer:

green

Explanation:

The electric field is all around the balloon and paper including between them, where, depending on their charge, there would be a force of either attraction or repulsion.

An electric field is the physical field that surrounds electrically charged particles and exerts force on all other charged particles in the field, either attracting or repelling them.

Thus, for the charged balloon and a charged piece of paper 0.04 m away, we can conclude that, the electric field is all around the balloon and paper including between them, where, depending on their charge, there would be a force of either attraction or repulsion.

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Answer:

A. boi-gas

Explanation:

This may help u

Answer:

292.31 m/s

Explanation:

If Distance (d) = 190m

Time (t) = 1.3s

Speed of sound in air (v) =?

then

2d=vt

v=2d/t

v= 2×190/1.3

v=292.31 m/s

The total change in velocity of the satellite is 23 m/s

In Physics, Impulse is the product of mass and change in velocity

Given:

mass = 46 kg

Impulse = 1035 kg•m/s

change in velocity = ?

impulse = mass * velocity

change in velocity = Impulse / mass

change in velocity = 1035 / 45

change in velocity =  23 m/s

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The volume of the material that must be used to make a star with the mass of the sun is 1.2×10⁵¹ m³.

Volume is the amount of space occupied by an object or a plane figure.

To calculate the volume of the material that must be used to make a star with the mass of the sun, we use the formula below.

Formula:

Where:

Make V the subject of the equation

From the question,

Given:

Substitute these values into equation 2

Hence, The volume of the material that must be used to make a star with the mass of the sun is 1.2×10⁵¹ m³.

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According to Newton's third law

So

[tex]\\ \rm\dashrightarrow F_{A}=-F_A[/tex]

As car is pushed forward so the opposing force is less than 8000N

Answer:It is less than 8,000 N and greater than zero.

Explanation:

Hypotenuse be H

Apply Pythagorean theorem

[tex]\\ \sf\Rrightarrow H^2=P^2+B^2[/tex]

[tex]\\ \sf\Rrightarrow H^2=5^2+9^2[/tex]

[tex]\\ \sf\Rrightarrow H^2=25+81[/tex]

[tex]\\ \sf\Rrightarrow H^2=106[/tex]

[tex]\\ \sf\Rrightarrow H=\sqrt{106}cm[/tex]

Increasing the temperature causes an increase in the average kinetic energy of the particles of a material.

The average kinetic energy of particles is the energy possessed by particles due to their constant motion.

The constant motion of particles occurs due to the energy acquired by the particles, when the temperature of the particles increases, the average kinetic energy increases which in turn increases the speed of the particles.

Thus, we can conclude that, increasing the temperature causes an increase in the average kinetic energy of the particles of a material.

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Answer:

47

Explanation:

48km:1hr (10sec×60min=600hr)

¥ :600hr

1hr÷¥=1. 48×600÷1=2800

2800÷60=47

47 will be the acceleration

[tex]\text{Initial velocity,}~ u = 0 ~ ms^{-1}\\\\\text{Final velocity,}~ v = 48~kmh^{-1} = \dfrac{48\times 1000}{3600} ms^{-1} = 13.33 ms^{-1}\\ \\\text{Time,}~ t = 10~ sec\\\\\text{Acceleration,}~ a = \dfrac{v-u}{t} = \dfrac{13.33-0}{10} = \dfrac{13.33}{10} = 1.33 ~ ms^{-2}\\\\\text{Hence the acceleration of the car is}~ 1.33 ~ms^{-2}.[/tex]

The normal force of the ferris wheel on a 10kg toddler at the very bottom of the ferris wheel is 102.41 N.

The normal force of the ferris wheel on a 10kg toddler at the very bottom of the ferris wheel is calculated as follows;

Fn = Fc + mg

Fn = mω²r + mg

where;

Fn = 10(0.21²) 10  + 10(9.8)

Fn = 102.41 N

Thus, the normal force of the ferris wheel on a 10kg toddler at the very bottom of the ferris wheel is 102.41 N.

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Answer:

The reflection and rectilinear propagation of light helps in the formation of shadows and also tells light doesn't penetrate opaque materials.

Based on the data provided, the value of the constant b is 3.27 × 10^-5 kg/s and the time required to reach 63% of terminal velocity is 0.58 s.

The terminal velocity of a body is the velocity at which the body falls at constant velocity through a fluid.

For the falling raindrop, let positive direction be downwards and negative direction upwards,

The raindrop experiences a downward gravitational force mg, and an upward drag force -bv.

The total force at a time t is given as

a)

Terminal velocity is achieved then the total force is 0,

0 = mg - bv0

Therefore

b = mg/v0

Substitutingthe values:

b = (3 × 10^-5 × 9.8)/9

b = 3.27 × 10^-5 kg/s

b) Applying Newton's Second Law

F = ma

where

Therefore,

mg = mv/t t = v/g

however, t is at 63% velocity

thus:

t = 0.63v/g

t = 0.63 × 9 /9.8

t = 0.58 s

Therefore, the value of the constant b is 3.27 × 10^-5 kg/s and the time required to reach 63% of terminal velocity is 0.58 s

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#1

Yes gravity is acting downwards

#2

#3

#4

$5

No Applied force

Answer:

the two types of materials interacting (described by the coefficient μk) and how hard these two surfaces are pushed together (the normal force)

hope this helps and is it needs more let me know

Answer:

0.175 second

Explanation:

i hope it helps

For a twin mass of 30.9 kg, sitting at a distance of 1.85 m, with a horizontal force of 59.0 N  the ratio of Serena's speed to Sallie's speed  is mathematically given as

V= 2.06:1

Generally, the equation for the velocity   is mathematically given as

v = w r

Therefore

[tex]\frac{v serena}{vsallie} = \frac{r serena}{r sallie}[/tex]

V= 3.63/1.76

V= 2.06

In conclusion,  the ratio is

V= 2.06:1

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Answer:

load

a generator, a light bulb (load) and a closed switch

Explanation:

as explained in the other question, the fan is using generated electric energy to create mechanical movement. as such it is a load on the grid or circuit or net.

and electric power can only flow, if there is a closed (uninterupted) circuit from the power source to a load and back.

any open switch is an interruption of the circuit.

a buzzer is a kind of switch. it closes the circuit (and puts a load on) only when somebody presses it.

by the way, a closed circuit without a load will "destroy" (short circuit) the power source or at least the wires (burn through).

Answer:

0.035

Explanation:

7÷1000

=0.007m

0.007/0.2

=0.035

Mechanical strain of an elastic substance is the ratio of its change in length to the original length. The strain of the elastic string of length 20 cm when stretched by 7 mm is 0.035.

Strain is a physical quantity used to express the change in dimension of an elastic material. It is the ratio of change in length to the original length. Stress is the force that causing the deformation.

According to Hook's law of elasticity, the strain is directly proportional to the strain. They show a linear relation. Let L be the original length of a string and its change in length be ΔL.

Thus, strain = ΔL / L

Given that, the change in length = 7 mm = 0.7 cm

original length of the string = 20 cm

strain = 0.7 cm/ 20 cm

         = 0.035

Therefore, the strain of the elastic string of length 20 cm when stretched by 7 mm is 0.035.

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Answer:

A) nucleus, ribosomes, and chloroplasts

B) mitochondria, cell wall, chloroplasts

D) cell membrane, ribosomes, small vacuoles

E) cell wall, central vacuole, and cell membrane

Explanation:

It cannot be C as the list features centrioles, which is an animal-cell only structure.

Answer:

Newton

Explanation:

The SI unit for weight is newton.