how can I get good grades in physics?​

Answer:

A light ray is a line (straight or curved) that is perpendicular to the light's wavefronts

Explanation:

Have a great day.

Answer:

20Amp

Explanation:

Using the transformer formula

Vs/Vp = Ns/Np = Ip/Is

Vs/Vp = Ip/Is

Vp is the primary voltage = input voltage

Vs is the secondary voltage = output voltage

Ip is the current in the primary coil

Is is the amount of current in the secondary coil.

If the transformer doubles its input voltage Vp, its output voltage Vs will be

decreased by 2 but the output current will be doubled

Given the input current Ip = 10A, the current in the secondary coil (output current) will be doubled i.e Is = 2(10) = 20A

The current in the secondary coil be "50 A". To understand the calculation, check below.

According to the question,

Current in primary coil, [tex]I_{in}[/tex] = 10 A

We know the relation,

Power = [tex]V_{in} I_{in}[/tex] = [tex]V_{out} I_{out}[/tex]

then,

→ [tex]V_{in} I_{in}[/tex] = [tex]V_{out} I_{out}[/tex]

By substituting the values,

   [tex]V_{in}[/tex] × 10 = 2 [tex]V_{in} I_{out}[/tex]

By applying cross-multiplication,

           10 = 2 [tex]I_{out}[/tex]

         [tex]I_{out}[/tex] = [tex]\frac{10}{2}[/tex]

                = 5 A

Thus the response above is correct.

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Answer:

Explanation:

If you look at the chemistry behind most brake fluid, it comes from the combination of various types of glycols, which are basically a mixture of non-petroleum and other alcohol-based fluids. After a mixing process, the chemical name gets shortened to “polyglycol”. In addition, there are also high-grade silicone-based fluids, which cannot be mixed with any other type of fluid. So whether it's used in the brake or clutch system, it's important to understand the differences between these common types of brake fluid.

The brake fluid must maintain specific properties. Our brakes can get hot, sometimes up to 1200 degrees, so the fluid needs a high boiling point. Also, because our vehicles experience seasons just as we do, it’s important to have low freezing point as well. On top of maintaining both extremes, it's designed not to damage any rubber components in the brake system.

As a result, the chemical properties found in most brake fluids can permanently dull or damage paint. So be sure to handle with care and be quick to clean any accidental overspills. Brake fluid is hydroscopic, meaning it has a natural tendency to absorb moisture. And over enough time the added moisture can result in corrosion build up or a decreased boiling point. It’s never a bad idea to change your brake fluid every couple of years and try not to leave your reservoir cap off any longer than needed

Answer: high operation temperatures, good low-temperature and viscosity-temperature properties, physical and chemical stability, protection of metals from corrosion, inactivity with respect to mechanical rubber articles, and lubricating effect

Hope this helps

Answer:

fundamental quantity can simply be defined as an independent quantity while derived quantity is dependent i.e. the derive their quantities from the fundamental

Answer:

B

Explanation:

The method used by the student to test his claim is  determine how dissolving salt in water affects the specific heat. The correct option is fourth.

The specific heat is the amount of heat required to change the temperature by 1°C. It is denoted by C.

A student claims that water's polarity is the reason it has a high specific heat.

Polarity is determined by the salt dissolved in water. So, to determine how dissolving salt in water affects the specific heat is best method.

Thus, the fourth option is correct.

Learn more about specific heat.

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Answer:

A. Pu -239

Explanation:

An isotope is an element with the same atomic number but different mass number. most isotope are unstable, having short half life.

Curium-242 is an isotope produced when Plutonium 239 is bombarded by an alpha particle. This reaction between Plutonium 239 and alpha particle gives curium-242, neutron and a high amount of energy as the products.

Curium oxidizes easily, and it is a dangerous metal which can cause cancer initiation when absorbed by biological materials e.g bones or tissue.

Answer:

Voltage.

Explanation:

Answer:x rays are electromagnetic waves.

x rays are transverse waves

x rays travel at the speed of light

Explanation:

Answer:

The water particles move in the same direction as the vibrating source of the sound wave. ... What best describes the waves produced by the tuning fork? mechanical, because the vibrating tuning fork makes air molecules around it vibrate. A wave is produced in a Slinky as shown.

Explanation:

Answer:

mechanical, because the vibrating tuning fork makes air molecules around it vibrate

Explanation:

Answer:

bigger instruments make lower pitches

Explanation:

bass drums and other large instruments have low sounds because they're so big. the smaller the instrument is, the higher pitch it's going to have

Answer:

It is mostly the Bass instruments because they use mouthpieces while the wind instrument use reeds and make a higher pitched sounds

Explanation:

Band

The atomic number of a nucleus decreases during:

A. Nuclear fission and alpha decay

Alpha decay is an atomic rot process where a shaky core changes to one more component by shooting out a molecule made out of 2 protons and 2 neutrons. This catapulted molecule is known as an alpha molecule and is just a helium core.

It changes or 'rots' into an alternate nuclear core, with a mass number that is decreased by four and a nuclear number that is diminished by two.

Thus, option A is correct.

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Explanation:

The relation between potential difference, current and resistance flowing in a circuit is given by using Ohm's law. It can be given by :

V = IR

[tex]I=\dfrac{V}{R}[/tex]

Resistance opposes the flow of electric current in the circuit. It means that, if resistance is more, less current will flow through the circuit.

Answer:

a. V = (a - b)d/2ε₀ b. 2ε₀A/d

Explanation:

a. The potential difference between the plates

Using Gauss' law, we first find the electric field between the plates

ε₀∫E.dA = Q where Q = charge enclosed, E = electric field

Now Q = [a +(-b)]A = (a - b)A where + a and -b are the surface charge densities of the plates and A is the area of the plates.

ε₀∫E.dA = Q

ε₀∫EdAcos0 + ε₀∫EdAcos0 = (a - b)A

ε₀E∫dA + ε₀E∫dA = (a -b)A

ε₀EA + ε₀EA = (a -b)A

2ε₀EA = (a -b)A

E = (a - b)/2ε₀

We now find the potential difference, V between the plates from

V = ∫E.dl

V =E∫dl

V = Ed  where ∫dl = d the distance between the plates.

V = (a - b)d/2ε₀

b. The capacitance between them

Capacitance C = Q/V

= (a - b)A ÷ (a - b)d/2ε₀

= 2ε₀A/d

Answer:

Decreases

Explanation:

Viscosity is inversely proportional to temperature

i.e. η ∝ [tex]\frac{1}{T}[/tex]

Where η is coefficient of viscosity and T is temperature,

Which means that when temperature increases, viscosity decreases and vice versa.

Answer:

The hunter should aim directly at the perched monkey because the tranquilizer dart will fall away from the line sight at the same rate that the monkey falls from its perch.

Tan theta = 9 / 90 = .1      so theta = 5.71 deg

The time for the monkey to reach the ground is

t = (2 h / g)^1/2 = (18 / 9.8)^1/2 = 1.36 sec

So the horizontal speed of the dart must be at least

Vx = 90 m / 1.36 sec = 66.4 m/s

Vx = V cos theta

V = 66.4 m/s / cos 5.71 = 66.7 m/s

The angle of projection of the tranquilizer dart is 5.7⁰

The horizontal speed of the tranquilizer dart is 66.5 m/s

The given parameters;

The angle of projection of the tranquilizer dart is calculated as;

[tex]tan(\theta) = \frac{y}{x} \\\\tan(\theta) = \frac{9}{90} \\\\tan(\theta) = 0.1\\\\\theta = tan^{-1}(0.1)\\\\\theta = 5.71 ^0[/tex]

The speed of the tranquilizer dart is calculated as;

X = v₀ₓt

where;

t is the time to reach maximum height

X is the horizontal displacement = 90 m

The time to reach maximum height is calculated as;

[tex]h = v_0_yt + \frac{1}{2} gt^2\\\\h = 0 + \frac{1}{2} gt^2\\\\h = \frac{1}{2} gt^2\\\\t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2\times 9}{9.8} } \\\\t = 1.36 \ s[/tex]

The horizontal speed of the tranquilizer dart is calculated as;

[tex]X = v_0cos(\theta) \times t\\\\90 = v_0\times cos(5.71) \times 1.36\\\\90 = 1.353 v_0\\\\v_0= \frac{90}{1.353} \\\\v_0 = 66.5 \ m/s[/tex]

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Answer: Cut down on watching tv, sitting down for more than 30 minutes at a time, and playing video games.

Explanation:

Answer:

A

Explanation:

Use the conservation of energy formula to calculate the velocity of the ball when it reaches the halfway point (10m down). Then, use your calculated value to obtain the kinetic energy.

Answer:

A. 49 on Plato

Explanation:

Its the right one trust me .

Answer:

The new force becomes 3 times of the initial force.

Explanation:

Let q₁ and q₂ are two charged particles. The force between them is given by :

[tex]F=\dfrac{kq_1q_2}{r^2}\ ......(1)[/tex]

If [tex]q_1'=\dfrac{q_1}{4}[/tex]

and

[tex]q_2'=3q_2[/tex]

Also, r' = r/2

New force,

[tex]F'=\dfrac{kq_1'q_2'}{r'^2}[/tex]

Putting all the above values,

[tex]F'=\dfrac{k\dfrac{q_1}{4}3q_2}{(r/2)^2}\\\\F'=3\times \dfrac{kq_1q_2}{r^2}\\\\F'=3F[/tex]

So, the new force becomes 3 times of the initial force.

Answer:

Explanation:

Sounds travel faster in object having high density proportion or matter. This is because particles vibrates and causing the other particle near to as well vibrate. Hence, when sound is moving from a higher dense medium like Water, the rate of traveling is high compare to it moving in air with less dense.

Answer:

a=9.8 ms−2 12^2=0^2+2×9.8×H

H=7.35m

Explanation:

To find the height the following formula should be used: v2=u2+2aH

Assuming this occurs on earth,

Answer:

7.3 m

Explanation:

Answer:

Fgrav. = GM1×M2/R2

Explanation:

Gravitational force is mostly related

to planetary bodies by Newton's law of gravitation which states that the gravitional force is proportional to the product of the mass of the object and inversely proportional to the square of the distance between them.

Hence in this case the Gravitational force,

Fgrav. = GM1×M2/R2

M1 and M2 are the mass of the two students and R is their distance apart

G is a constant known as gravitational constant.6.67408 × 10-11 m3/kgs2

Answer:

C

Explanation:

Environmental factors provides ambiguity a particular one could be studied to see how it affects recyclable plastics.

[tex]answer = 5 \: \: metre \: per \: second\\ distance = 2000 \: m \\ time = 400 \: seconds \\ velocity = \: \frac{distance \:t ravelled}{time \: taken} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = \frac{2000}{400} \\ \: \: \: \: \: \: \: \: \: = 5 \: metre \: per \: second \\ hope \: it \: helps[/tex]

Explanation:

R = [tex]\sqrt{(12.0)^{2} + (9.00)^{2}}[/tex] = 15 UNIDADES

Answer:

A fraction of the wave will be reflected at the junction and the remainder will be transmitted through the junction into the thin rope

Explanation:

When the junction of the thin and the thick rope is reached by the wave, the wave behaves in the following two ways;

1) A fraction of the incident wave from the thick rope to the junction/boundary of the thin rope will be reflected back to in the direction of the thick rope with a lower amplitude and upright

2) A fraction of the incident wave from the thick rope to the junction/boundary of the thin rope will be transmitted through the thin rope such that the transmitted pulse on the thin rope will have an higher amplitude than that of the thick rope due to the available energy in the wave pulse and the lesser weight of the thin rope.

Answer: 29.17m/s^2

Explanation:

Given the following :

Velocity = 525 m/s

Time = 18 seconds

Acceleration = change in Velocity with time

Using the motion equation:

v = u + at

Where v = final Velocity

u = Initial Velocity and t = time

Plugging our values

525 = 0 + a × 18

525 = 18(a)

a = 525 / 18

a = 29.166666

a = 29.17 m/s^2

Answer:

475 J

Explanation:

Kinetic energy is calculated by one half of the product of mass and velocity squared or expressed as:

KE = 1/2 (mv²)

We calculate as follows:

KE1 = 1/2 (mv²) = 1.9 * 10^3 joules

KE2 = 1/2 (m(v/2)²) = 1/2 (mv²/4)

KE2 =  1.9 * 10^3 joules / 4 = 475 J

Answer:

Since air resistance actually stops vehicles and goes in a vector opposite to the direction of the vehicle and slows it down. Vehicles would want to make vehicles aerodynamic. Many cars bump into air molecules therefore making air resistance. Aerodynamic cars will lesser the allowance of bumping into said molecules. Thats why cars like to cut down on air resistance

Air resistance is friction.  

-- Friction steals kinetic energy.

-- A car gets kinetic energy by burning gasoline, and uses the kinetic energy to get where it needs to go.  

-- If anything steals the car's kinetic energy, then the car has to burn more gasoline to get where it needs to go.

-- Gasoline costs money.

-- Anything that steals a car's kinetic energy costs you more money to operate the car.

(Another thing that takes kinetic energy away from the car is the car's brakes. The driver uses the brakes when he WANTS to slow down or stop, so it's not stealing, but it still costs kinetic energy and money.)

Answer:

a) Shadow distance

10 cm in front of the mirror.

b) Zoom in the shadow

The shadow formed is the same height as the object and is placed also at the centre of curvature of the mirror as shown in the attached image to this solution.

c) The nature of the shadow

The shadow formed is real, inverted, same size as the object and formed at the centre of curvature.

Explanation:

English Translation

Objects as high as 3 cm are placed at a distance of 10 cm in front of a concave mirror with 10 cm curvature. Determine:

a) Shadow distance

b) Zoom in the shadow

c) The nature of the shadow

Solution

The mirror equation is given as

(1/f) = (1/v) + (1/u)

f = focal length of the mirror = (radius of curvature)/2 = 10/2 = 5 cm

v = image distance = ?

u = object distance = 10 cm

We can then calculate the shadow' s distance from the mirror thus

(1/5) = (1/v) + (1/10)

(1/v) = 0.2 - 0.1 = 0.1

v = (1/0.1) = 10 cm

b) Zoom in the shadow

Since the object is placed at the centre of curvature, as shown in the attached image, the image is formed at a point of intersection of rays. The image formed is the same height as the object and is placed also at the centre of curvature of the mirror.

c) The nature of the shadow

Since the mirror is a concave mirror, the image is real and formed in front of the mirror. The image is also inverted and formed at the centre of curvature of the mirror.

Hope this Helps!!!