Please select the word from the list that best fits the definition

Creates an image that is reflected through a focal point
A) Plane mirror
B) concave mirror
C) diffuse reflection
D) Specular reflection

Pls help :'(

The racket applies an average acceleration of

\(a_{\rm ave} = \dfrac{\Delta v}{\Delta t} \\\\ a_{\rm ave} = \dfrac{40\frac{\rm m}{\rm s} - \left(-30\frac{\rm m}{\rm s}\right)}{5.2\,\rm ms} = \dfrac{40\frac{\rm m}{\rm s} - \left(-30\frac{\rm m}{\rm s}\right)}{0.0052\,\rm s} = 13,461.5\dfrac{\rm m}{\mathrm s^2}\)

(Note that I'm taking the initial direction of the ball's motion to be negative.)

Then the average force exerted on the ball is

\(F_{\rm ave} = ma_{\rm ave} \\\\ F_{\rm ave} = (58.0\,\mathrm g)a_{\rm ave} = (0.058\,\mathrm{kg})a_{\rm ave} \approx \boxed{780\,\mathrm N}\)

Answer:

a for the first one b for the second

Hi there!

Recall the equation for momentum:
\(\large\boxed{p = mv}\)

p = linear momentum (kgm/s)
m = mass (kg)

v = velocity (m/s)

We can calculate each object's momentum and compare.

Cement truck:
\(p = 20000 \cdot 5 = 100000kg\frac{m}{s}\)

Race car:
\(p = 1000 \cdot 90 = 90000 kg\frac{m}{s}}\)

Since 100,000 > 90,000, the cement truck has the greater momentum.

Show us the experiment then

Answer:

6650km

Explanation:

Distance = (6.4 × 10³ + 250) km

= 6650 km

Because the net force must be zero, we conclude that the magnitude of the force is 1500 newtons, and the direction is in the positive axis.

By Newton's laws, we know that if the net force applied to an object is different than zero, then the object is accelerated.

In this case, we know that the object moves with constant velocity, so there is no acceleration, meaning that the net force is equal to zero.

Then we must have:

F1 + F2 + F3 = 0N

Replacing F1 and F2 we get:

-3000 N + 1500N + F3 = 0

F3 = 3000N - 1500 N = 1500N

Then the magnitude of the force is 1500 newtons, and the direction is in the positive axis.

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Scientists believe that a long time ago the seven continents might have been connected, but they think the plates shifted apart at some point.

Answer:

a=Head

b=Tip

c=South pole of the magnet

d=North pole of the magnet

Answer:

It is 3 m/s² downward.

Explanation:

The mass of an object, m = 30 kg

Upward force, F = 200 N

Downward force, F' = -300 N

We need to find the magnitude and direction of its acceleration.

Net force = F+F'

= 200+(-300)

= -100 N

We know that,

Force, F = ma, a is acceleration of the object

\(a=\dfrac{F}{m}\\\\a=\dfrac{-100}{30}\\\\a=-3.33\ m/s^2\approx -3\ m/s^2\)

Hence, the acceleration is -3 m/s² and it is acting in the downward direction.

To calculate the percent crystallinity of branched polyethylene, you need to know its density. However, the density alone is not sufficient to determine the crystallinity.

Crystallinity is usually determined using techniques such as X-ray diffraction or differential scanning calorimetry. These techniques analyze the polymer's structure and thermal behavior to determine the percentage of crystalline regions.

If you have additional information, such as the degree of branching or molecular weight, please provide it so that I can assist you further. Crystallinity is usually determined using techniques such as X-ray diffraction or differential scanning calorimetry (DSC).

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Answer:

Positive

when a negatively charged rod is bring near uncharged spherical conductor it attracts positive charge and repels negative charges

so In left side all positive charges appears and in right side all negetive

Types of methods of charging

The Buoyant force operates on an item when it is immersed in a fluid (liquid or gas), and it is equal to the weight of the fluid displaced by the object. You may use the following formula to determine buoyant force:

Buoyant force equals the weight of the fluid displaced by the item.

The object's displacement of fluid equals the density of the fluid times the volume of fluid displaced. As a result, the formula for determining buoyant force is as follows:

Buoyant force = fluid density x volume displaced x gravity

where gravity is the gravitational acceleration.

To use this method, you must first determine the density of the fluid as well as the volume of fluid displaced by the item. The volume of fluid displaced equals the volume of the submerged item in the fluid. If the entire item is submerged, the volume of fluid displaced equals the object's volume.

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Answer:

Explanation:

1. He had the opportunity to have a chance of doing experimental research where he began to develop a theory on electromagnetism. He was then recognized in 1884 and appointed to chair of physics at Cavendish Laboratory. In 1914 there was a new type of physics that lead to more questions than there were answers for and that is when Thomson began associating himself with this new type of physics.

2. Thomson began experimenting with the cathode ray tubes that showed him that all atoms contain small negatively charged particles/electrons. His proposition to the atom was shown with is plum pudding model, which showed negatively charged electrons that were embedded in a positive charge. His discovery came before the discovery of the atomic nucleus that would be included in the electron in the atomic model.

3.His contributions to the atomic model include that all matter is made of atoms, atoms are invisible and indestructible, all atoms in a certain element are identical, two or more atoms that are combined form a compound, and a chemical reaction is the rearrangement of the atoms. His ideas of the atomic model that do not exist in the modern day atomic model include the fact that the distribution of the negative and positive particles was not uniform.

Websites:

https://socratic.org/questions/why-was-j-j-thomson-wrong

https://www.khanacademy.org/science/ap-chemistry/electronic-structure-of-atoms-ap/history-of-atomic-structure-ap/a/discovery-of-the-electron-and-nucleus#:~:text=Summary-,J.J.,positively%2Dcharged%20%22soup.%22

The resultant velocity of the aircraft is 3015 Km/hr while the direction is 5.7 degrees North of east

The resultant  vector is that vector that has the same effect is magnitude and direction as the two vectors acting together. Recall that velocity is a vector quantity. This implies that the magnitude and the direction of the velocity is very important.

The resultant velocity would now be obtained by considering the directions of the two velocities hence we have to work geometrically and not algebraically. We have to know that the plane is flying east at 3000 km/h. If the plane encounters a cross-wind of 300 km/h that is directed to the north

Thus the resultant velocity is;

R = √(3000)^2 + (300)^2

R = √9 * 10^6 + 9 * 10^4

R = 3015 Km/hr

The direction of this resultant velocity is;

Tan-1 (300/3000)

= 5.7 degrees North of east

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Answer:

c and d

what i would do is ask the coach if you could take a minute to stretch and as soon as posible jump into the game

Explanation:

i play soccer lol

Answer: i'm pretty sure its  warm up your muscles before playing

Explanation:

if you don't u get hurt.

In an advertisement claims that a centrifuge takes up only 0.127m of bench space but can produce a radial acceleration of 3000g (g= 9.8m/s^2) at 5000 rev/min. To evaluate the claim's realism, we compare the claimed radius of 0.127 meters (12.7 centimeters) with the calculated radius of 0.0812 meters (8.12 centimeters).

We can determine the required radius of the centrifuge using the formula for radial acceleration, which is given by:

a = ω² * r

Here, 'a' represents the radial acceleration, 'ω' denotes the angular velocity, and 'r' represents the radius of the centrifuge.

Given information:

Radial acceleration (a) = 3000g = 3000 * 9.8 m/s²

Angular velocity (ω) = 5000 rev/min = (5000 rev/min) * (2π rad/rev) * (1 min/60 s)

To convert angular velocity to rad/s, we use the conversion factor:

ω = (5000 rev/min) * (2π rad/rev) * (1/60 min/s)

Now we can proceed to calculate the required radius:

3000 * 9.8 = [(5000 rev/min) * (2π rad/rev) * (1/60 min/s)]² * r

Simplifying the equation, we have:

3000 * 9.8 = (5000 * 2π / 60)² * r

Solving for 'r', we get:

r = (3000 * 9.8) / [(5000 * 2π / 60)²]

Calculating the value of 'r', we find:

r ≈ 0.0812 meters

Therefore, the required radius of the centrifuge is approximately 0.0812 meters or 8.12 centimeters.

To evaluate the claim's realism, we compare the claimed radius of 0.127 meters (12.7 centimeters) with the calculated radius of 0.0812 meters (8.12 centimeters). Since the calculated radius is smaller than the claimed radius, it suggests that the claim is unrealistic.

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A certain spring stretches 7.7 cm when it supports a mass of 0.51 kg . if the elastic limit is not reached, The string will go 150.80 cm  when it supports a mass of 10 kg

Force 1 = - k x1

mass * acceleration =  - k x1

0.51 * 9.8 = - k (7.7)

k = 0.65

Force 2 = - k x2

10 * 9.8 = - 0.65 x2

x2 = 150.80 cm

The string will go 150.80 cm  when it supports a mass of 10 kg

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Answer:

Explanation:

equal in magnitude and opposite in direction

Astronomers observe several characteristics of stars to determine if they are main sequence or evolved giants. One key characteristic is their luminosity, which is the total amount of energy that a star emits per second.

Main sequence stars, such as our sun, have a relatively constant luminosity that is determined by their mass and composition. Evolved giants, on the other hand, have a much higher luminosity due to the nuclear fusion of heavier elements in their cores.
Another characteristic that astronomers observe is a star's color. Main sequence stars have a characteristic range of colors that are determined by their surface temperature. For example, cooler stars appear reddish while hotter stars appear bluish-white. Evolved giants, on the other hand, can vary in color depending on their temperature and the types of elements that are present in their outer layers.
Astronomers also look at a star's size and mass to determine whether it is a main sequence star or an evolved giant. Main sequence stars have a relatively stable size and mass that is determined by their position on the Hertzsprung-Russell diagram. Evolved giants, however, can have sizes that are hundreds of times larger than the sun and masses that are significantly greater as well.
Overall, astronomers use a combination of observations of luminosity, color, size, and mass to determine whether a star is a main sequence star or one of the evolved giants. These observations help us to better understand the life cycles of stars and the various stages they go through as they evolve.

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Answer:

The horizontal component of the velocity is approximately 13.22 m/s

Explanation:

The velocity of the kick which the football player gives the ball = 21 m/s

The angle of the path taken by the ball = 51°

The velocity can be represented vectorially, showing the vertical and horizontal components as follows;

v = 21 × cos(51°)·\(\hat i\) + 21 × sin(51°)·\(\hat j\)

Where we have;

The horizontal component of the velocity = 21 × cos(51°)

The vertical component of the velocity = 21 × sin(51°)

Therefore;

The horizontal component of the velocity = 21 × cos(51°) ≈ 13.22 m/s

The horizontal component of the velocity ≈ 13.22 m/s.

Answer:

180 m

Explanation:

i found the formula

Answer:

Where is the question??

Answer:

Elements in a family have the same

Ans C. number of valence electrons

Vector quantities include displacement, force, torque, momentum, acceleration, and velocity. A physical quantity that has both directions and magnitude is referred to as a vector quantity.

Summary. Any quantity with magnitude and direction, such displacement or velocity, is referred to as a vector quantity. Mathematical entities referred to as vectors are used to express vector quantities. Geometrically, a vector is represented by an arrow with an arrowhead at the end.

displacement, such as 50 kilometers east. velocity, for instance, 11 m/s and above. acceleration, for instance 9.8 m/s2 of downward motion momentum, such as 250 kg m/s (kg meters per second) in the south west.

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The work done by the drag force from the air is negative

When a skydiver descends towards the earth with a parachute open, there are two main forces acting on the skydiver: the gravitational force pulling the skydiver towards the earth and the drag force from the air resistance acting in the opposite direction to the motion. The drag force is proportional to the velocity of the skydiver and is directed opposite to the velocity vector. As the skydiver descends, the velocity decreases, and so does the magnitude of the drag force.

The work done by a force is defined as the product of the force and the displacement of the object in the direction of the force. In the case of the drag force acting on the skydiver, the direction of the force is opposite to the direction of the displacement.

In other words, as the skydiver descends, the drag force from the air resistance does negative work on the skydiver, which means that it reduces the kinetic energy of the skydiver. This is why a skydiver gradually slows down as they approach the ground, even with an open parachute.Therefore, the work done by the drag force is negative.

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The broken pieces of the plates overlie a ductile layer known as asthenosphere.

Plate tectonics is a scientific hypothesis that explains the movement of Earth's lithosphere. Plate tectonics also explains the formation of mountains, volcanoes, and the occurrence of earthquakes. The Earth's lithosphere is composed of the Earth's crust, both continental and oceanic, and the uppermost part of the mantle. The lithosphere is divided into several plates that fit together like a puzzle. These plates are in constant motion, driven by the motion of molten rock in the Earth's mantle.

The plate boundaries can interact with one another in various ways. Divergent plate boundaries are where new lithosphere is created as the plates move apart. At convergent plate boundaries, one plate is forced beneath another. Transform plate boundaries are where plates slide past each other in a sideways movement.

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