A ball is dropped from the roof of a 25-m-tall building. What is the velocity of the object when it touches the ground? Suppose the ball is a perfect golf ball and it bounces such that the ve locity as it leaves the ground has the same magnitude but the op posite direction as the velocity with which it reached the ground How high will the ball bounce? Now suppose instead that the ball bounces back to a height of 20 m. What was the velocity with which it left the ground?

Answer:

But negative acceleration means that the rate of change of velocity is negative or velocity decreases. Example: (1) When we apply brakes in a moving car, then negative acceleration acts on it and the car stops. (2) When we throw a ball upwards, then also negative acceleration acts on it.

Explanation:

If it helps you mark me as a brainleast

MATHEMATICALLY A NEGATIVE ACCELERATION MEANS YOU WILL SUBTRACT FROM THE CURRENT VALUE OF THE VELOCITY.

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

Resistivity R = K * L / A    where resistivity is constant for material, L the length of the material and A the area of the material

K = R * A / L     where R is the resistance of the material

Explanation:

p = F /A

F = P×A

F = 30,000 Pa / 0.1 m²

F = 300,000 N

Answer:

  an object sliding down hill

Explanation:

On a slope, the force applied is due to gravity. Its direction is straight down. If the object is sliding down the hill, its displacement is at an angle to the applied force. The angle of displacement will depend on the steepness of the hill.

Answer:

D) crystalline solid that conducts current under certain conditions

Explanation:

A semiconductor is any crystalline solid material whose electrical conductivity is intermediary between that of insulators and conductors. That is, a semiconductor does not conduct like a conductor but does more than an insulator.

Based on this, a semiconductor is said to only conduct electricity under certain conditions as opposed to conductors that do so under any condition. Example of semiconductors are silicon, carbon, antimony, arsenic etc.

Answer:

This is because these metals are used for minting (making) coins.

Answer:

It is bcz it is used for making coins

Answer:

Obeying to weights & measurement regulations in both national and international metrology legislation, standards and test procedures is a requirement to participate in any market because it's aimed to safeguard the consumers and promote fair competition, which provides efficiency and saves unnecessary costs to U.S. businesses and stakeholders.

Explanation:

In the U.S., the National Institute of Standards and Technology (NIST) has an Office of Weights and Measures (OWM) that represents the country in the International Organization of Legal Metrology (OIML)

Answer:

the process of comparing unknown quantities with known standards quantities are known as measurement

Answer:

Resistance is defined as the property of a conductor to resist the flow of charges through it. The resistance of conductor is numerically given as the ratio of potential difference across its length to the current flowing through it.

Explanation:

Answer:

d. No, porque la ecuación de trabajo lo define.

Explanation:

En Física, el trabajo realizado se puede definir como la cantidad de energía transferida cuando un objeto o cuerpo se mueve a lo largo de una distancia debido a la acción de una fuerza externa.

Matemáticamente, el trabajo realizado viene dado por la fórmula;

[tex] W = F * d [/tex]

Dónde;

Por lo tanto, podemos deducir de la definición de trabajo y su fórmula que el trabajo se realiza cuando un objeto (cuerpo) se mueve una distancia o experimenta cualquier forma de desplazamiento mientras transfiere energía.

The magnitude (size or numerical value) and the direction.

Hope this helps!!! :)

Answer:

define 1 second time

One second is the time that elapses during 9,192,631,770 (9.192631770 x 10 9 ) cycles of the radiation produced by the transition between two levels of the cesium 133 atom. ... One second is equal to 1/86,400 of a mean solar day.

Answer:

One part of 86400 part of a day is called one second time.

✌✌✌✌

Answer:

yes water was discovered in mars

Answer:

[tex]F = kmg \\ k = \frac{F}{mg} [/tex]

Explanation:

F = k . m . g

=> F = k . mg

[tex] = > k = \frac{F}{mg} (ans)[/tex]

Answer:

Three

Explanation:

I hope this helps:)

Answer:

42g

Explanation:

the mass of a body is given by

m=weight/gravity

=420/10

=42

I hope this helps

Answer:

difference between mass and weight is that mass is amount of matter in a material while weight is a measure of how the force of gravity acts upon that mass.the mass of an object will be same on earth and mars but its weight on both planets will be different.

That's a parallel circuit. (B)

When current from Point-A reaches the 3-way intersection just to the right of Point-B, it has to make a choice:  Either turn left, go through B, and light the lower bulb, or go straight and light the upper bulb.

A circuit that has any "decision" points in it is a parallel circuit.  What happens in the real world is:  The current splits up.  Some of the current that reaches the intersection turns left toward Point-B, and the rest of it goes straight up.

A series circuit is one in which there's only one possible path all the way around.  There are no intersections of more than 2 roads, and no electron ever has to decide which way to flow.

An open circuit is one in which there's a break somewhere along the line and electrons can't jump across it.  It's like a railroad where a big piece is cut out of the track somewhere.  So no trains can travel on that route, and there's no current flowing anywhere in the circuit.

I'm not so sure about a "combination" circuit.  I guess you could give that name to a complicated circuit that has some series parts and some parallel-parts.  Personally, I'd call that a "series-parallel" circuit.  But it really doesn't matter right now.  Whatever the word means, the circuit in the picture is definitely not a "combination" circuit.

Answer:

B. Parallel Circuits

Explanation:

A parallel circuit is constructed by connecting the terminals of all the individual load devices so that the same value of voltage appears across each component. In a parallel circuit, charge divides up into separate branches such that there can be more current in one branch than there is in another.

hope i helped

Answer:

The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of gravitation and its relation to other forces of nature.It applies to the cosmological and astrophysical realm, including astronomy.

The theory transformed theoretical physics and astronomy during the 20th century, superseding a 200-year-old theory of mechanics created primarily by Isaac Newton. It introduced concepts including spacetime as a unified entity of space and time, relativity of simultaneity, kinematic and gravitational time dilation, and length contraction. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves

Answer:

38500

Explanation:

I looked it up so it may be wrong

Answer:

I. Period = 1.3 seconds

II. Frequency = 0.769 Hertz

Explanation:

Given the following data;

Number of oscillation = 240 cycles

Time = 5.2 minutes.

Conversion:

1 minute = 60 seconds

5.2 minutes = X seconds

X = 60 * 5.2

X = 312 seconds

To find the following;

I. Period

Mathematically, the number of oscillation of a pendulum is given by the formula;

[tex] Number \; of \; oscillation = \frac {Time}{Period} [/tex]

Making period the subject of formula, we have;

[tex] Period = \frac {Time}{Number \; of \; oscillation} [/tex]

Substituting into the formula, we have;

[tex] Period = \frac {312}{240} [/tex]

Period = 1.3 seconds

II. Frequency

[tex] Frequency = \frac {1}{Period} [/tex]

Substituting the values into the formula, we have;

[tex] Frequency = \frac {1}{1.3} [/tex]

Frequency = 0.769 Hertz

Answer:

Below

Explanation:

To solve for d rearrange the formula v = (d)(t) to:

  d = v / t

I'm not to sure if you are using different variables but usually in physics the formula for velocity is v = d / t not v = dt

If you wanted to solve for displacement you would do:

  d = (v)(t)

Hope this helps!

Answer:

b. the seasons

Explanation:

Let F₁ and F₂ denote the two forces, and R the resultant force.

F₁ and F₂ point perpendicularly to one another, so their dot product is

F₁ • F₂ = 0

We're given that one of these vectors, say F₁, makes an angle with R of 30°, so that

F₁ • R = ||F₁|| ||R|| cos(30°)

But we also have

F₁ • R = F₁ • (F₁ + F₂) = (F₁ • F₁) + (F₁ • F₂) = F₁ • F₁ = ||F₁||²

So, knowing that ||R|| = 100 N, we get that

(100 N) ||F₁|| cos(30°) = ||F₁||²

(100 N) cos(30°) = ||F₁||

||F₁|| ≈ 86.6 N

(And the same would be true for F₂.)

Answer:

hi

Explanation:

pls mark as a BRAINLIST

Answer:

im pretty sure that it's (A.) High current

Explanation:

pf

not 100% sure, tho