30. A box with mass 20kg is on a cement floor. The coefficient of static friction between the box and floor is 0.25. A man is pushing the box with a horizontal force of 35N. What is the magnitude of the force of static friction between the box and floor

Answer:

1) a ray parallel to the optical axis that after passing through the lens passes through the focal length

2) a ray that passes through the center of curvature, this ray does not have any deviation

real image   d_{objet} > f

Explanation:

In geometric optics, you can find the position of the image by geometric method, we draw two rays

1) a ray parallel to the optical axis that after passing through the lens passes through the focal length

2) a ray that passes through the center of curvature, this ray does not have any deviation

3) a ray that passes through the focal length and when passing the lens comes out horizontally

The interceptor point is where the image is

To determine if the image is real or virtual, when the object is at a greater distance than the focal length, the image is real and when it is at a shorter distance, the image is virtual.

The virtual image is formed on the same side as the object

real image   d_{objet} > f

Answer:

C

hope that helped! ^^

Answer:

The work done is doubled.

Explanation:

The work done is defined as the product of the force and the displacement in the direction of force.

Work = force x displacement.

As the force is doubled and the displacement remains same, so the work done is also doubled.

Work done is a scalar quantity and its SI unit is Joule.

Answer:

B, A, E, D, C

Explanation:

If the arrow points to the right, then the force is positive.

If the arrow points to the left, then the force is negative.

Also, remember that the force does not relate (necessarily) to the mass, so the different blocks having different masses is not an important factor in this problem.

Let's find the force in each block.

A)

Here we have a positive force of 3N and a negative force of 1N

Then the net force (the sum of all the forces) is:

F = 3N  - 1N = 2N

B)

Here we have two positive forces, one of 1N and other that I cant see, I guess that it is 3N

Then the net force is:

F = 1N + 3N = 4N

C)

Here we have two negative forces of 2N

Then the net force is:

F = - 2N + ( - 2N) = -4N

D)

Here we have a single force of 2N that is negative, then the net force is:

F = -2N

E)

Here we have a negative force of 3N and a positive force of 2N

then the net force is:

F = -3N + 2N = -1N

Then, the order of greatest to least (from positive to negative) is:

B, A, E, D, C

Answer:

hard2

Explanation:

Answer:

Explanation:  

Answer:

The answer is below

Explanation:

The density of an object is its mass per unit volume, that is the ratio of mass to volume occupied. It is given by:

Density = mass / volume

A body floats in a liquid when the buoyant force (weight of displaced liquid) is more than the weight of the body, it sinks if the buoyant force is less than the weight of the body and remains at the same depth if the buoyant force is equal to the weight of the body.

The density of Kerosene is less that the density of water. So a body displaces a greater weight of water than that of kerosene, and hence floats in water but sinks in kerosene.

Answer:

Those who survived the bomb may become deaf or blind, as well as suffer catastrophic burns and injuries. Even people who were not seriously injured could become trapped within a structure or unable to navigate through the wreckage.

Explanation:

Answer:

1. Yes

2. Yes

3. 292 joules

4. 90 watts

5. By increasing the force

Explanation:

Have a wonderful day :)

Answer:

The acceleration is 1 cm/s^2.

Explanation:

The acceleration is defined as the rate of change of velocity.

Here, initial velocity, u = 3/1 = 3 cm/s

final velocity, v = 4/1 = 4 cm/s

time, t = 1 s

Let the acceleration is a.  

Use first equation of motion

v =  u + at

4 = 3 + 1 x a

a = 1 cm/s^2

Answer:

10.

parabolic

11.

Entirely horizontal

12.

45°

Answer:

F = ⅔ F₀

Explanation:

For this exercise we use Coulomb's law

         F = k q₁q₂ / r²

let's use the subscript "o" for the initial conditions

          F₀ = k q² / r²

now the charge changes q₁ = q₂ = 2q and the new distance is r = 3 r

we substitute

          F = k 4q² / 9 r²

          F = k q² r² 4/9

          F = ⅔ F₀

Answer:Graffiti and street art embody cultural significance through its individualistic nature, though its ability to beautify and enhance public spaces, when you see graffiti you might think to yourself, "dang that looks cool"

Explanation:

Answer:

Explanation:

solve the parallel resistances

30||40     and 50||30

17.14285714   and 18.75

total Resistance = 35.89285714

V = IR

9V = I *35.89285714

9V / 35.89285714 = I

0.250746 = I

Now use the resistance across AB

V = 17.14285714 * 0.250746

V = 4.29850

this is the Voltage drop across AB  :P

Answer:

fingers bc when u put out your right hand it would be your fingers

Explanation:

Answer:

false gravity is not considered matter

Explanation:

Use Ohm's Law

V / R = I

I = 5A

V = 110V

R =?

Solve for R

if you need further help let me know

Answer:

65 deg C = 35 deg C below boiling

35 deg C = 35 * 9 deg F / 5 deg c = 63 below boiling deg F

(1 deg C = 9/5 deg F)

212 - 63 = 149

So 65 deg C = 149 deg F

Not sure exactly what's wanted, but

212 deg F   =     boiling

65 deg C = 149 deg F

Check:  65 * 9/5 + 32 = 149       as found above

Answer:

65 deg C = 35 deg C below boiling

35 deg C = 35 * 9 deg F / 5 deg c = 63 below boiling deg F

(1 deg C = 9/5 deg F)

212 - 63 = 149

So 65 deg C = 149 deg F

Not sure exactly what's wanted, but

212 deg F   =     boiling

65 deg C = 149 deg F

Check:  65 * 9/5 + 32 = 149       as found above

Explanation:

Explanation:

jdjdjdkdixnxkakdjxjsjwosk

Answer:

e jiio7ruetw5258o0pomnmitwq2690okm ,,kkkiiht44456

The current across a certain resistor can be found using Ohm's Law, as before:

Vi = RiIi

where:

Vi  is the voltage drop across the resistor

Ri is the resistance of the resistor

Ii is the current through the resistor

In this problem:

R2 = 8Ω is the resistor we are considering

V₂ = 110V is the voltage drop across that resistor (in a parallel circuit, the voltage drop is the same across each resistor)

Solving for I, we find the current through it:

I₂ = V₂/R₂ = 110/8 = 13.7A (see that "V₂/R₂" and "110/8"  part as fraction)

Answer:

small amounts of mass are converted to large amounts of energy

Explanation:

According to the mass-energy equivalence, which Albert Einstein initially proposed as a general principle. It was revealed that mass and energy are connected and that a "small amount of mass can be converted into enormous amounts of energy."

Using the formula E=mc^2. This means Energy equals mass times the speed of light squared.

Hence, it is true that "small amounts of mass are converted to large amounts of energy."

Answer:

Thus, the maximum height is 7.35 m.

Explanation:

initial velocity, u = 12 m/s

acceleration due to gravity, g = 9.8 m/s^2

Velocity at maximum height, v = 0 m/s

Let the maximum height is h.

Use third equation of motion

[tex]v^{2}=u^{2}-2 g h\\0 = 12\times 12 - 2 \times 9.8\times h\\h =7.35 m[/tex]

Answer:

Explanation:

work done per unit time is caleed power.it's SI unit is watt.it depends upon time.

Answer:

I think it might be 8kg grams because it is bigger

Answer:

Explanation:

The formula for Kinetic Energy is

[tex]KE=\frac{1}{2}mv^2[/tex]. Filling in:

[tex]KE=\frac{1}{2}(1200)(20)^2[/tex] It looks like we only need 1 significant digit here but I'll give you 2 and you can round how you want.

KE = 2.4 × 10⁵ J

Answer:

The answer is "telescopes".

Explanation:

Throughout ancient times, astronomical observatories have indeed been available, and so many historical locations were reserved for astronomical observations. All contemporary astronomers lacked within those older telescopes were lenses until 1610. A telescope is indeed an instrument used to view far-off objects. Telescopes often are being used to look at planets and stars.