Like chargers attract one another

9514 1404 393

Answer:

  0.2 m/s

Explanation:

The average velocity is the change in position divided by the change in time:

  (8 m -4 m)/(20 s) = (4/20) m/s = 1/5 m/s = 0.2 m/s

The boy's average velocity is 0.2 m/s.

Answer:

Atoms in a solid are close and tightly packed.They vibrate about fixed positions .They are arranged in a regular LATTICE.They cannot be compressed nor can they change shape.They have strong forces of attraction between them so they cannot move in order to move they have to gain ENERGY. Whereas the atoms in a liquid are not that close compared to the ones in solid.They take the shape of the container but their volume remains fixed.They have weak forces of attraction between atoms and have more energy which enables them to move.

Explanation:

Answer:

The second choice

Explanation:

I think the answer is the second choice because if the surface is smooth, there is less friction. With a boat, it is easier to pull it on water than on the sand, because water has less friction, and thus, the answer is the second choice because rough surfaces have more friction.

Hopefully the explanation and answer helps!

Answer:

The size of the magnetic force on the wire due to the Earth's magnetic field is 4.62 × 10⁻⁶ N.

Explanation:

To determine the size of the magnetic force on the wire due to the Earth's magnetic field,

The magnetic force is given by the formula

F = ILB sinθ

Where F is the magnetic force on the wire

I is the electric current in Amperes (A)

L is is the length of wire in meters (m)

B is the magnetic field in Tesla (T)

and θ is the angle between current and magnetic field

From the question,

L = 0.30 m

I = 0.50 A

B = 0.50 gauss = 0.5 × 10⁻⁴ T (NOTE: 1 Gauss = 10⁻⁴ Tesla)

θ = 38°

Now, putting the values into the equation

F = ILB sinθ

F = 0.50 × 0.30 × 0.5 × 10⁻⁴ sin38°

F = 7.5 × 10⁻⁶ (0.61566)

F = 4.62 × 10⁻⁶ N

Hence, the size of the magnetic force on the wire due to the Earth's magnetic field is 4.62 × 10⁻⁶ N.

Answer:

The table is 2.08 m high

Explanation:

Horizontal Motion

When an object is thrown horizontally with a speed vo from a height h, the range or maximum horizontal distance traveled by the object can be calculated as follows:

[tex]\displaystyle d=v\cdot\sqrt{\frac {2h}{g}}[/tex]

If we know the range d = 0.15 m and the speed v = 0.23 m/s, we can solve the above equation for h:

[tex]\displaystyle h=\frac{d^2\cdot g}{2v^2}[/tex]

[tex]\displaystyle h=\frac{0.15^2\cdot 9.8}{2\cdot 0.23^2}[/tex]

[tex]\boxed{h=2.08\ m}[/tex]

The table is 2.08 m high

¡Hellow!

How we know, for calculate density, we can use the formule:

                                               [tex]\boxed{\textbf{p = m / v} }[/tex]

Where:

[tex]\sqrt{[/tex] p = Density = ?

[tex]\sqrt{[/tex] m = Mass = 57,9 g

[tex]\sqrt{[/tex] v = Volume = 3 cm³

Let's replace according we information:

p = 57,9 g / 3 cm³

p = 19,3 g/cm³

The density of the metal bar is 19,3 g/cm³.

¿Good luck?

Answer:

  about -1.26 m/s²

Explanation:

The acceleration can be found from the formula ...

  a = (v2² -v1²)/(2d)

Here, we have the initial velocity v1=23 m/s, the final velocity v2=0, and teh distance d=210 m. Using the formula, we find the acceleration to be ...

 a = (0 -23²)/2(210) ≈ -1.2595 . . . m/s²

Answer:

equal, opposite

Explanation:

Newton’s third law says that every time there is an interaction force, there is also a force that is equal in size and acts in the opposite direction .

Answer:

A

Explanation:

Switches are used to block electrical currents, thus needing to be made out of insulating material.

Answer:

1- bounce rule

2- left

3-11,2

4-true

5- whiffle ball

6- kitchen

7-false

8- ping pong

9- true

10- true

Explanation:

I'm pre5sure they are all right. brainliest please

Answer: I had the same quiz too I’m only doing so the other guy can get brainliest

Explanation:Kfkfkfjgjggj

Answer:

20.83rad/s

Explanation:

Using the law of conservation of momentum

m1u1+m2u2 = (m1+m2)v

m1 and m2 are the mass of the disc and Brick respectively

u1 and u2 are the linear velocities respectively

v is their final velocity of the block-disc system

Given

m1 = 100kg

m2 = 20kg

u1 = wr =25×1.6

u1 = 40m/s

u2 = 0m/s (brick is stationary)

Substitute and the final linear velocity v

100(40)+20(0) = (100+20)v

4000 = 120v

v = 4000/120

v = 33.3m/s

From the formula;

v = wr

w = v/r

w= 33.3/1.6

w = 20.83rad/s.

Hence the final angular speed of the disc-brick system is 20.83rad/s

Answer:

The new freezing point of water is -0.476°C.

Explanation:

Given that,

Mass of water = 4.62 kg

Mass of CaBr₂ = 236.5 g

We need to calculate the molality of solution

Using formula of molality

[tex]m=\dfrac{mass\ of\ CaBr_{2}}{molar\ mass\ of\ CaBr_{2}\times mass\ of\ water}[/tex]

Put the value into the formula

[tex]m=\dfrac{236.5}{200\times4.62}[/tex]

[tex]m=0.256\ mol/kg[/tex]

[tex]m=0.256\ m[/tex]

We need to calculate the depression in freezing point of water

Using formula of freezing point

[tex]\Delta T=m\times k[/tex]

Where, k = depression constant

m = molality of solution

Put the value into the formula

[tex]\Delta T=0.256\times1.86[/tex]

[tex]\Delta T=0.476^{\circ}C[/tex]

We know that,

The standard freezing point of water is 0°C

We need to find the new freezing point of water

Using formula for freezing point of water

Freezing point of 4.62 kg of water = freezing point of water-depression in freezing point of water

[tex]\Delta T'=0-\Delta T[/tex]

Put the value into the formula

[tex]\Delta T'=0-0.476[/tex]

Hence, The new freezing point of water is -0.476°C.

Answer:

it will take half of the initial time to reach double the velocity

Explanation:

Given that a car accelerates from rest to a certain velocity in a certain time.

Since the car accelerate from rest, the initial velocity U = 0

Using the first equation of motion,

V = U + at

V = at

Assume that there is no friction, and that the engine power is constant. Consider the following scenarios independently. How long would it take to reach double the velocity (also from rest)

That is V = 2V

Using the same formula ,

2( at ) = at

2T = t

T = t/2

Therefore, it will take half of the initial time to reach double the velocity

Answer:

answer: 105 sin 30 = 52.5

Hellow!

First, lets recabe information:

m (mass) = 1500 kg

a (aceleration) = 3 m/s²

F (Force) = ?

For calculate Force, if we have mass and aceleration, we can applicate the second law of Newton:

"Force is proportional to the product of the mass plus aceleration."

In a equation, this is like:

F = m * a

Let's replace according we information, and let's resolve:

F = 1500 kg * 3 m/s²

F = 4500 N

Result:

The force applicated is of 4500 Newtons.

Gud Luck!

If the free ends of conduction tester are connected for long time , The cell of the battery will drain very quickly

Which object? More information is needed to answer this question

Answer:

the set of all real numbers

Explanation:

Given the cost of the magazine expressed as:

c=45+3.75m where:

c describes the cost of the yearly subscription.

m is the amount of order.

You must understand that domain are the values of the input variable m that will make the function exist.

The value of m that will produce a positive output since we can only have a positive value of the cost. According to the option, we can say that the domain is on the set of all real numbers (some are negative but all positive real numbers)

Answer:

44.3 m/s

Explanation:

a) Draw a free body diagram of the mass M.  There are three forces:

Weight force mg pulling down,

Normal force N pushing perpendicular to the ramp,

and tension force T pulling parallel up the ramp.

Sum of forces in the parallel direction:

∑F = ma

T − Mg sin 30° = 0

T = Mg sin 30°

T = Mg / 2

Draw a free body diagram of the hanging mass m.  There are two forces:

Weight force mg pulling down,

and tension force T pulling up.

Sum of forces in the vertical direction:

∑F = ma

T − mg = 0

T = mg

Substitute:

mg = Mg / 2

m = M / 2

M = 2m

b) Velocity of a standing wave in a string is:

v = √(T / μ)

T = mg, and m = 5 kg, so T = (5 kg) (9.8 m/s²) = 49 N.  Therefore:

v = √(49 N / 0.025 kg/m)

v = 44.3 m/s

Answer:

-) It is less than 8 [N]

See the explanation below.

Explanation:

To solve this problem we must analyze each of the answers, and in this way, we will come to the right solution. The most important thing is to keep in mind that the body is moving to the left.

-) It is equal to 8 [N]

This answer is not possible, since if the Force F was equal to 8 [N] the body would be in equilibrium and the body would not move.

-)  It is equal to 10 [N]

This answer is not possible, since if Force F is greater than 8 [N] the body would move to the right.

-)  It is greater than 10 [N]

This answer is not possible, since if Force F is greater than 8 [N] the body would move to the right.

-) It is less than 8 [N]

This is the correct option, as the force of 8 [N] will move the body to the left.

Answer:

an electro magnet is technology contain at least one permanent magnet

If we assume the collision to be elastic the final velocity of the ball will be  -8.65 m/s, therefore the correct option is D.

It is a type of Collison for which the momentum, as well as the kinetic energy after and before the collision, is constant. there is no loss of energy in a perfectly elastic collision.

By using the law of conservation of momentum

momentum before collision = momentum after the collision

the initial momentum of rocket +initial momentum, of ball = final momentum of rocket + final momentum of the ball

By substituting the respective values

-1.75 + 0.00684 = -1.25 + m*v

-1.75 + 0.00684 = -1.25 + 0.057*v

v = -8.65 m/s

Thus, the final velocity of the ball is -8.65 m/s

Learn more about elastic collision

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Answer:

[tex]h_p = 30.46\ m[/tex]

Explanation:

Free Fall Motion

A free-falling object refers to an object that is falling under the sole influence of gravity. If the object is dropped from a certain height h, it moves downwards until it reaches ground level.

The speed vf of the object when a time t has passed is given by:

[tex]v_f=g\cdot t[/tex]

Where [tex]g = 9.8 m/s^2[/tex]

Similarly, the distance y the object has traveled is calculated as follows:

[tex]\displaystyle y=\frac{g\cdot t^2}{2}[/tex]

If we know the height h from which the object was dropped, we can solve the above equation for t:

[tex]\displaystyle t=\sqrt{\frac{2\cdot y}{g}}[/tex]

The stadium is h=32 m high. A pair of glasses is dropped from the top and reaches the ground at a time:

[tex]\displaystyle t_1=\sqrt{\frac{2\cdot 32}{9.8}}=2.56\ sec[/tex]

The pen is dropped 2 seconds after the glasses. When the glasses hit the ground, the pen has been falling for:

[tex]t_2=2.56 - 2 = 0.56\ sec[/tex]

Therefore, it has traveled down a distance:

[tex]\displaystyle y=\frac{9.8\cdot 0.56^2}{2} = 1.54\ m[/tex]

Thus, the height of the pen is:

[tex]h_p = 32 - 1.54\Rightarrow h_p=30.46\ m[/tex]

The pen is 30.52 m above the ground.

Given that the height of the stadium is h = 32m

The initial velocity of the glasses will be 0.

[tex]h=\frac{1}{2}gt^{2} \\t=\sqrt{\frac{2h}{g} } \\t=\sqrt{\frac{2*32}{9.8} }\\t=2.55s[/tex]is the time taken for the glasses to hit the ground.

Now the pen is released 2 seconds later. So by the time the glasses hit the ground the pen has spent:

[tex]t^{'}=2.55-2\\t^{'}=0.55s[/tex]in the air

distance traveled by the pen:

[tex]d=\frac{1}{2}gt^{2}\\\\d=\frac{1}{2}*9.8*0.55*0.55\\\\d=1.48m[/tex]

So the pen is  [tex]h-d=32-1.48=30.52m[/tex]  above the ground.

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Answer:

19.3 m/s

Explanation:

Take down to be positive.  Given:

Δy = 19 m

v₀ = 0 m/s

a = 9.8 m/s²

Find: v

v² = v₀² + 2aΔy

v² = (0 m/s)² + 2 (9.8 m/s²) (19 m)

v = 19.3 m/s

Answer:I think the answer is 5.43 I don’t rlly know

Explanation:

Answer:

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

[tex]a = \frac{f}{m} \\ [/tex]

where

m is the mass

f is the force

We have

[tex]a = \frac{275}{18} \\ = 15.277777...[/tex]

We have the final answer as

Hope this helps you

The kinetic energy of a body determines it's level of impact on the object in which it comes in contact with. Hence, the much larger kinetic energy exhibited by a wrecking ball compared to a yo-yo means that is has a much larger impact on a building than a yo-yo.

The kinetic energy of a body is a factor of it's velocity and mass as they are directly proportional.

The wrecking ball has a very large mass which is thousands of times larger than that of a yo-yo. Also, the velocity at which a wrecking ball is launched is higher than the velocity of a yo-yo.

This means that the kinetic energy of a wrecking ball is much higher than that of yo-yo. Hence, having much greater impact on a building compared to a yo-yo.

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Answer:

Explanation:

in this problem, we are expected to solve for the maximum height of a projectile (the ball)

Firstly, the expression for maximum height is

h = u ^2 *sin ^2 θ /2 g

Given data

initial velocity u=22m/s

angle of projection, θ= 40degrees

substituting into the expression we have

h = 22^2 *sin (40)^2 /2 *9.81

h = 484*0.413 /19.62

h =199.892 /19.62

h=10.18m

The maximum height is 10.18m

The maximum height attains by ball is 48.64 meter.

The maximum height is given by using formula,

                  [tex]h=\frac{u^{2}*sin2\theta }{g}[/tex]

Where u is initial velocity, and value of [tex]g=9.8m/s^{2}[/tex]

Given that,   [tex]u=22m/s,\theta=40,g=9.8m/s^{2}[/tex]

Substituting above values in formula.

             [tex]h=\frac{(22)^{2}*sin80 }{9.8} =\frac{484*0.98}{9.8} =48.64m[/tex]

Hence, the maximum height attains by ball is 48.64 meter.

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