4. ____________ occurs when one object slides over another.
a. Sliding friction
b. Static friction
c. Rolling friction
d. Net force

Answer:

i) O m/s² as velocity is constant

ii) 20m/s

iii)Hint:Calculate the area of the graph,that is;below the line, for the first 15 seconds only

Hope this helps.

The boat has to pull with MORE force. Don't forget about the force of friction with the water, pulling the skier in the backwards direction. The force that accelerates him is the NET force ... boat force minus water resistance. So the boat force has to be greater than the net accelerating force.

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!!!

Answer:

Final velocity (v) = 36 m/s

Distance traveled (s) = 2,160 m

Explanation:

Given:

Initial velocity (u) = 0

Acceleration (a) = 0.3 m/s

Time travel (t) = 2 minutes = 120 seconds

Find:

Final velocity (v) = ?

Distance traveled (s) = ?

Computation:

v = u + at

v = 0 + 0.3(120)

v = 0.3(120)

v = 36 m/s

Final velocity (v) = 36 m/s

Distance traveled (s) = ut + (1/2)at²

Distance traveled (s) = (0.5)(0.3 × 120 × 120)

Distance traveled (s) = 2,160 m

Explanation:

they would formulate a new hypothesis with the same dependent variable but a different independent variable as a virginal hypothesis .

Answer:

Infinity = Never ending

Explanation:

The universe could be infinite, both in terms of space and time, but there is currently no way to test whether it goes on forever or is just very big. The part of the universe we are able to observe is finite, measuring about 46 billion light years in diameter.

The set of natural numbers is an infinite set. This kind of infinity is, by definition, called countable infinity. All sets that can be put into a bijective relation to the natural numbers are said to have this kind of infinity. This is also expressed by saying that the cardinal number of the set is aleph-naught (ℵ0).

Hope this helps. Mark as brainliest!

STARS ARE INFINITE , NUMBERS ARE INFINITE

Explanation:

Answer:

a. 6 A

b. 3 V

Explanation:

a. By using Kirchoff's Junction Rule, which states that the current flowing into a junction must equal the current flowing out of it. As you can see in the first 3-way split, the current splits into 3A, 2A, and 1A. This means that when the 3 wires rejoin, the current must have a magnitude equal to the total of the current flowing in all 3 branches, which would equate to 3+2+1 = 6 A.

b. Voltage differences across branches of a parallel circuit are identical. This means that we can treat the 3 resistors as one, and say that the voltage drop across that whole area is 3 V. Since that is the only voltage drop in the circuit, the battery's voltage drop must also be 3 V to equate to it. This is explained by Kirchoff's Loop Rule.

Answer:

The magnitude of acceleration is 2m/s² .

Explanation:

First, you have to find the velocity as it starts to travel 200m in 10s. The formula of velocity is V = Distance/Time, then you have to substitute the values into the formula :

[tex]v = d \div t[/tex]

[tex]let \: d = 200 \\ let \: t = 10[/tex]

[tex]v = 200 \div 10[/tex]

[tex]v = 20m/s[/tex]

Next, you have to substitute the values into the acceleration formula, a = (v-u)/t where v represents final velocity, u is initial velocity and t is time taken :

[tex]a = \frac{v - u}{t} [/tex]

[tex]let \: v = 20 \\ let \: u = 0 \\ let \: t = 10[/tex]

[tex]a = \frac{20 - 0}{10} [/tex]

[tex]a = \frac{20}{10} [/tex]

[tex]a = 2m/ {s}^{2} [/tex]

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:

2) C would need the least effort, because the longer the effort distance, the least the effort applied.

Answer:

I think it is better if you read and shortly write my explanation

Explanation:

simple pendulum with no friction, mechanical energy is conserved. Total mechanical energy is a combination of kinetic energy and gravitational potential energy. As the pendulum swings back and forth, there is a constant exchange between kinetic energy and gravitational potential energy.

because as the distance increases the gravitational force decreases so the weight of a body decreases

Answer:

Weight of the body decreases with increase in distance from the Earth because weight is inversely proportional to distance from the Earth which means Weight of the body decreases with increase in distance from the Earth and vice versa. Also Weight is "gravitational force exerted on the body" so as the distance from the Earth increases , the "gravitational force" decreases.

Answer:

1298.5watt

Explanation:

Power is defined as the rate at which work is done

Expressed mathematically as;

P = F × d/ t; F = force or weight of object ;d is height or distance sustain and t is time covered

Hence for 1 person the power consumption is ;

Note weight =mass× acceleration of free fall due to gravity,g

g is known as 9.8m/S2

Time taken is 1min which is 60 sec

60 ×9.8 × 5.3/60 = 51.94 watt

Hence for 25 persons we have

25 × 51.94 =1298.5watt

1.3kilo watt( kilo is 1000)

The work done by the escalator is 3,080.4 joules and the power requirement of the escalator to move 25 passengers every minute is approximately 51.34 watts.

The Work Done is calculated as:

Force (F) = 60 × 9.8

Distance (d) = 5.30 meters

Work (W) = F × d

Work (W) = (60 × 9.8) × 5.30

Work (W) = 3,080.4 joules

The Power is calculated as:

Time (t) = 1 minute

Power (P) = Work / Tim (t)

Power (P) = 3,080.4 / 60

Power (P) = 51.34 watts

Therefore, the power requirement of the escalator to move 25 passengers every minute is approximately 51.34 watts.

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Answer:

X: Absorbs energy from the core.

Y: Releases energy to the photosphere.

Explanation:

Convection is a mode of heat transfer through fluids (liquids or gas), and it requires material medium for its propagation.

The energy absorbed from the core of the Sun, is transferred through X (convection zone) by convectional process, and it flows to Y (radiative zone). Since the regions X and Y have different functions, the heat propagates from X causing photons to traverse through Y where it get released into the photosphere or the Sun's surface.

Therefore;

X: Absorbs energy from the core.

Y: Releases energy to the photosphere.

Answer:

X: Takes longer for photons to move through

Y: Releases energy to the photosphere

Explanation:

Answer:

  294.524 m^3

Explanation:

The volume of a cylinder is given by the formula ...

  V = πr^2h

For a radius of 2.5 m and a length of 15 m, the volume is ...

  V = π(2.5 m)^2(15 m) = 93.75π m^3 ≈ 294.524 m^3

The volume is about 294.52 cubic meters.

Explanation:

Veins carry deoxygenated blood from different parts of the body to our heart. ... Since a larger volume of blood is collected in the right auricle than that of the left auricle, right auricle is larger than the left auricle.

Answer:

B.The box experiences less friction on the marble floor

Explanation:

Answer:

B. The Box experiences less friction on the marble floor

Explanation:

This is because the the carpet is not a flat surface and the marble is smooth

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: - 452.088joule

Explanation:

Given the following :

Mass of water = 12g

Change in temperature(Dt) = (11 - 20)°C = - 9°C

Specific heats capacity of water(c) = 4.186j/g°C

Q = mcDt

Where Q = quantity of heat

Q = 12g × 4.186j/g°C × - 9°C

Q = - 452.088joule

Answer:

The wavelength of the wave is 2.34 nm.

Explanation:

It is required to find the wavelength of a [tex]1.28\times 10^{17}\ Hz[/tex] wave. A wave moves with a speed of light. Speed of a wave is given in terms of wavelength and frequency. So,

[tex]v=f\lambda[/tex]

[tex]\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{1.28\times 10^{17}}\\\\\lambda=2.34\times 10^{-9}\ m\\\\\text{or}\\\\\lambda=2.34\ nm[/tex]

So, the wavelength of the wave is 2.34 nm.

The wavelength of the wave is 2.34 × 10⁻⁹ meters.

Given the data in the question;

Wavelength; [tex]\lambda =\ ?[/tex]

To determine the wavelength of the wave, we use the expression for the relations between wavelength, frequency and speed of light.

[tex]\lambda = \frac{c}{f}[/tex]

Where [tex]\lambda[/tex] is wavelength, f is frequency and c is speed of light ( [tex]3*10^8m/s[/tex] )

We substitute our values into the equation

[tex]\lambda = \frac{3*10^8m/s}{1.28*10^{17}Hz} \\\\\lambda = \frac{3*10^8m/s}{1.28*10^{17}s^{-1}} \\\\\lambda = 2.34 * 10^{-9}m[/tex]

Therefore, the wavelength of the wave is 2.34 × 10⁻⁹ meters.

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Answer: - 7500N

Explanation:

Given the following :

Initial Velocity of car = 108km/hr

Time taken to stop after applying brakes = 4s

Mass of passengers in car = 1000kg

Force exerted by the brakes on the car =?

After 4s, then final Velocity (V) = 0

Initial Velocity (u) of the car = 108km/hr

108km/hr = (108 × 1000)m ÷ (3600)s = 30m/s

Force exerted = mass(m) × acceleration(a)

Acceleration of car = Change in Velocity with time

a = (v - u) / t

a = (0 - 30) / 4

a = - 30/ 4

a = - 7.5m/s^2

Therefore,

Force exerted = mass(m) × acceleration(a)

Force exerted = 1000kg × (-7.5)m/s^2

Force exerted = - 7500N

Answer:

The force exerted by the brakes on the motor car is -7500 N.

Explanation:

Given :-

To find :-

Solution :-

Since the car stops, the final velocity (v) will be 0 m/s.

• Initial velocity (u) = 108 km/h.

Converting initial velocity into m/s.

We know that,[tex] \sf{1\:km/h=\dfrac{5}{18}\:m/s}[/tex]

Then initial velocity,

= [108 × 5/18 ] m/s

= 30 m/s

Now find the force exerted by the brakes.

★ Formula used :

[tex]{\boxed{\sf{F=\dfrac{m(v-u)}{t}}}}[/tex]

[tex]:\implies \sf \: F= \dfrac{1000(0 - 30)}{ 4} \\ \\ : \implies \sf \: F \: = \dfrac{ - 30000}{4} \\ \\ : \implies \sf \: F \: = - 7500[/tex]

The force exerted by the brakes on the motor car = -7500 N.

•The negative sign of force(F) means that the force was applied in opposite direction of motion.

Acceleration = (change in speed) / (time for the change)

Change in speed = (speed after the change) - (speed before the change)

Change in speed = (65 m/s) - (35 m/s)  =  30 m/s

Acceleration = (30 m/s) / (5 s)

Acceleration = 6 m/s²

Answer:

space , small amount of gravity is found in the space ,infact we can say that there is no gravity in the space

Answer:

Poles

Explanation:

The gravitational force is maximum at the equator and minimum at the poles.

Explanation:

i think the sun is near the earth that's why we see the sun during the day and the moon is behind the sun so when it is in the night the moon will remove in front the sun and there will be night I hope it will help you

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:

P.E.=600Nm

Explanation:

m=30kg

g=10m/s²

h=2m

P.E.=?

as we know that

P.E.=mgh

P.E.=30kg×10m/s²×2m

P.E.=600Nm

Answer:

There is no answer, since a closed-pipe resonator can NOT have a second harmonic. However, if you were to plug the pipe length and the speed of sound into the closed-pipe equation anyway you would get 49.56 as your fundamental frequency, which means that 99.13 would be your "plug and play" 2nd harmonic.

Explanation:

Answer:

A

Explanation:

Answer: A

Explanation:

Answer:

-7500 N

Explanation:

v₀ = 108 km/h = 30 m/s

v = 0 m/s

t = 4 s

a = Δv / Δt

a = (0 m/s − 30 m/s) / 4 s

a = -7.5 m/s²

F = ma

F = (1000 kg) (-7.5 m/s²)

F = -7500 N

Answer:-7500

Explanation v₀ = 108 km/h = 30 m/s

v = 0 m/s

t = 4 s

a = Δv / Δt

a = (0 m/s − 30 m/s) / 4 s

a = -7.5 m/s²

F = ma

F = (1000 kg) (-7.5 m/s²)

F = -7500 N