A man whose mass is 74.7 kg runs up a flight of stairs and has a vertical gain of 19.9 m in a time of 12.5 s.
a. What power, in watts, is supplied by the force pushing up on the man? (Ignore gains or losses in kinetic energy.)
b. Suppose the man’s body is 41.2% efficient, so that just 41.2% of the energy supplied by his body is converted into mechanical power. How much total power is expended by his body, in watts? (P=___W)

At the base of the incline, Sam is moving at a speed of 15.73 m/s. who weighs 75 kg puts on his skis and begins to descend a 50 m-high, 20 frictionless slope.

Sam's bottom-of-the-screen speed is determined using the Work-Energy Theorem as follows: An object moves parallel to the plane on a slope with no friction. Both the normal force and the gravitational perpendicular component cancel each other out because they are acting in the same speed. Therefore, an object on a frictionless slope is solely accelerated by the gravitational parallel component. On a surface on an inclined plane with no friction, any item accelerates.

delta W is equal to the delta kinetic energy for frictionless slope

(36750 - 27472) = 1/2*75*(v2 -0).

9278=37.5(v^2)

v^2 = 9278/37.5(v2)

v^2 = 247.4v = 15.73 m/s

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Ratio of the speeds of the boats with equal centripetal acceleration is 0.7.

Centripetal acceleration is defined as the change in tangential velocity and is experienced during uniform circular motion. It has a magnitude equal to the square of the body's speed v along the curve divided by the radius r (or distance) from the centre of the circle to the moving body. The centripetal acceleration ac is given by:

ac = v^2/ r

For the boat A:

ac = va^2/ 120

For the boat B:

ac = vb^2/ 240

As provided, the centripetal acceleration is equal for both boats, hence

va^2/ 120 = vb^2/ 240

va^2/vb^2 = 120/240

va^2/vb^2 = 0.5

va/vb = √0.5 = 0.7

Hence, the ratio of the speeds of the boats is 0.7

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If you measure and calculate the density of a cube by the method of displacement, and then later use that same cube to measure and calculate the density by the method of flotation you should expect to obtain the same density.

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The minimum coefficient of friction between the tires and the road that the car could have and still make the turn is 0.7 for dry roads and 0.4 for wet roads.

The value of minimum coefficient of friction is usually between 0 and 1 but can be greater than one. A value of zero means there is no friction between the objects such is possible with a lubricant material . All objects, should have friction between them when they come in contact with each other.

The coefficient of friction is as low as 0.05 between dry sliding surfaces will be achieved when the mechanical interconnections are removed. This outcome has been attained based on a theoretical model of an ideal surface for low friction.

The coefficient of friction having value 1 is a perfect positive correlation. A coefficient of correlation zero means there is no linear relationship. Correlation coefficients are used in science to assess the degree of association between two variables, factors, or data sets.

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In drawing, the holding force is most likely to be lower than the maximal drawing force.

By using a special method called FORCE Drawing, you can learn to see things more clearly and to comprehend what you are looking at. This will help you to draw from life and from your imagination with great talent and understanding.

All forces operating on an item, their direction, and their magnitude are represented in a force diagram. The image has been streamlined to only depict the forces.

The term "force diagram," sometimes known as a free body diagram, refers to a sketch in which all force vectors acting on an object are shown with their initial points at the location of the object.

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64 N force would be required to make a mass of 8 kg accelerate at

8m/s².

The term "force" is defined precisely in science. It is acceptable to refer to a force of this level as a push or a pull. An item does not "have in it" or "contain" a force. Another item applies force to another. The concept of a force does not apply only to living or non-living entities.

The newton (sign N) is the SI unit of force.

The fundamental formula for force is F = ma, where F represents force, m represents mass in kilograms, and a represents acceleration in m×s⁻². It is the second law of motion established by Newton.

Given that,

Acceleration (a) = 8m/s²

Mass (m) = 8 kg

Force (F) = ?

As we know,

Force= mass × acceleration

F = 8 kg × 8 m/sec²

F = 64 N

Therefore, force of 64 N is required to accelerate the body.

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The angular momentum of the disk: 0881 kg*m^2/s.

In Newtonian mechanics, momentum is the made of the mass and velocity of an item. it's far a vector quantity, owning a value and a route. If m is an item's mass and v is its speed, then the object's momentum p is mathbf{p} = m mathbf{v}.

-A truck complete of goods has a huge mass and so it has to gradually down earlier than a prevent light as it has a massive momentum with the same speed and so it's far very difficult to forestall. -A shifting bullet has a large momentum since it has an extremely big pace although it consists of a very small mass.
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With a piece of cork connected, which has a mass of 15 g in air and a specific gravity of 0.25, the pair weighs 164.736 grammes when they are both submerged in water.

A physical body's mass is its total amount of matter. Inertia, or the body's resistance to acceleration (change of velocity) when a net force is applied, is also measured by this property. The gravitational pull an object has on other bodies is also influenced by its mass. A substance will float on water if its specific gravity is less than 1. sp gr, or specific gravity, is a common abbreviation. The following formula represents specific gravity, which is also known as relative density: Substance formula: substance / reference The purpose of comparing densities

60 grammes of water are equal to 15 grammes of cork when divided by 15.25. Lead's specific gravity is 11.35; its mass is (230+15)-(60+20.264); and its mass is 245 - (80.264) grammes.

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Force exerted by the ball on the rope is 24.5 N.

Force is an external influence that can change the velocity or motion of an object.

mass of the ball = 1.5 kg

Radius of the circle = 3 m

Speed at which the ball is rotating = 7 m/s

Since the ball is rotating in a vertical circle, centripetal force acts on it.

Centripetal force is the force exerted on a rotating object and the gravitational force in a vertical circle is zero.

Mathematically centripetal force is Fc = mv²/r

Fc = 1.5 * (7)²/ (3)

Fc = 24.5 N

Force exerted by the ball on the rope at the top of the vertical circle is 24.5 N.

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The two statements that accurately describes this variation are that low tides are lowest at both full moon and new moon, high tides are highest at both full moon and new moon.

What is the reason for this?

As the video shows, the tidal minima are smallest and the tidal bulges are largest at full moon and new moon, because those times when tidal forces due to the Sun and Moon get aligned (and therefore add to one another).

So, high tides are higher and low tides are lower at these times, and these are called spring tides. (In contrast, we have neap tides at first- and also third-quarter moons, when high tides are not as high and low tides are not as low as usual.)

Therefore, the two statements that accurately describes this variation are that low tides are lowest at both full moon and new moon, high tides are highest at both full moon and new moon are .

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Voltage is proportional to inductance just as, for resistors, it is proportional to resistance. Now, the (independent) voltages for parallel elements are equal (V₁ = V₂) and the currents (which are generally functions of time) add i(t) = i₁(t) + i₂(t)

This leads to the equation,

i = i₁ + i₂ + i₃ = V [(1/R₁) + (1/R₂) + (1/R₃)] for resistors.

We note that this condition on the currents implies

d₁(t)/dt + d₂(t)/dt = d(it)/dt

Thus, although the inductance equation, ε = -L(di/dt) involves the rate of change of current, as opposed to current itself, the conditions that led to the parallel resistor formula also apply to inductors.

Therefore, 1/L(eq) = 1/L₁ + 1/L₂

Therefore to ensure the independence of the voltage values, it is important that the inductors not be too close together. The requirement is that the field of one inductor not to have significant influence (or "coupling") in the next.

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The amplitude drops to one-quarter of the initial value after 102.7 oscillations.

λ=1/51⋅0.20slog(1/2)=−0.68s^-1

Using the previous result we can evaluate the amplitude as a function of time to obtain the elapsed time until the amplitude drops to one-quarter of its initial value,

1/4=Aeλt.

Solving for the time,

t=1/λlog(1/4)=20.4s

Comparing this result with the period,

t=102.7T.

The maximum displacement or distance made by a point on a vibrating body or wave relative to its equilibrium location is known as the amplitude in physics. It is equivalent to the length of the vibration path divided in half. Amplitude is the separation between the wave's resting position and its highest displacement. Frequency is the number of waves that cross a particular place in a second. Period—the length of time needed for a wave cycle to complete

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Applying the Work-Energy Theorem, the Work Done by a Non-Conservative Force is [tex]5.3 *10^{10}[/tex] J

The given Parameters are :

Initial Velocity (u) = 120 m/s

Final Velocity (v) = 7950 m/s

Mass (m) = 1770 kg

Displacement (h) = 146 km = 146000 m

According to the Work-Energy Theorem,

The Work Done is given by the difference between the final and initial Kinetic Energies,

Thus,

Work Done = Final Kinetic Energy - Initial Kinetic Energy

Now, Work done = Work done by gravity + Work Done by Non-Conservative Force

So, Work Done by gravity = mgh = 1770 *10*146000 =2482000000 J

Change in Kinetic Energy = [tex]\frac{1}{2} *m*(v^{2} -u^{2} )[/tex]

Putting the values, we get,

Change in Kinetic Energy = [tex]\frac{1}{2} *1770*(7950^{2} -120^{2} )=55921468500[/tex] J

Now, Work Done by Non Conservative Force = Change in Kinetic Energy-Work Done by gravity = 2482000000 - 55921468500 = 53439468500 = 5.3 * [tex]10^{10}[/tex] J

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The deceleration experienced by the cyclist is -5 m/s. Deceleration is also called negative acceleration.

Deceleration is the term used to describe a decrease in speed as the body moves away from the beginning place. The opposite of acceleration is deceleration.

Given,

Initial velocity (V₁) = 8 m/s

Final velocity (V₂) = 0 m/s (Since the bike was stopped).

Time taken for the velocity drop (t) = 1.6 seconds

We know,

[tex]deceleration=\frac{V_{2}-V_{1} }{t} \\[/tex]

Substituting the values we get,

[tex]deceleration= \frac{0-8}{1.6}[/tex]

[tex]= -5 m/s[/tex]

Hence, the deceleration experienced by the cyclist is -5 m/s.

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The right answer is "-1.5 m/s²"

Answer explanation:

Acceleration = change in velocity / time

= (4 m/s – 7 m/s) / 2 s = -1.5 m/s2.

The acceleration is negative because the bike is slowing down.(decelarating)

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The rank of the terrestrial planets based on their expected cooling rates, from fastest cooling to slowest cooling is as follows -

mercury , Mars, Venus, Earth

Mercury - It is the smallest terrestrial planet in the solar system. It has a thin atmosphere, which causes it to swing between burning and freezing temperatures.

Mars - It is less dense than Earth and has a smaller magnetic field, which is a indication of a solid core rather than a liquid one. Mars is known to have water ice and organics- some of the ingredients for living things.

Venus - It is about the same size as Earth and has a thick, toxic carbon-monoxide (CO) dominated atmosphere that traps heat, making it the hottest planet in the solar system.

Earth - Out of the four terrestrial planets, Earth is the largest and has regular seasons for much of it surface; regions closer to the equator tend to stay warm, while spots closer to the poles are cooler and in the winter, icy.

Therefore, the cooling rate of terrestrial planets is Mars, Earth, Venus, Mercury

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When the block  of iron is  placed  in water  the volume of water that   is  displaced is 27.0  cm³

Hence, Option D is correct.

Explain in detail.

therefore the volume displaced = 27 cm³  since the volume of water displaced  is equal to  volume of block.

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The correct answer is only within a narrow path on earth. This is because the shadow of the earth during a total lunar eclipse is only large enough to cover a small area on the earth's surface.

A total lunar eclipse is visible only within a narrow path on earth, where the moon passes directly through the center of the Earth's shadow. This path, which is typically around 160 to 270 kilometers (100 to 170 miles) wide, moves eastward as the Moon orbits Earth.

During a total lunar eclipse, the moon is fully engulfed in Earth's shadow, making it visible to observers on a whole hemisphere of earth. However, an opportunity to observe the solar corona is not visible during a total lunar eclipse. The solar corona can only be seen during a total solar eclipse.

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I don't see a picture attached to your question. Without one, I don't think I will be able to determine what type of orbit is displayed.

The total kinetic energy of a cylinder is 15 J.

Given that, mass = 5 kg

Radius of the cylinder= 30 cm = 30/100 m = 0.3 m

Speed = 2 m/s

Ut = Uk + Ur

where, Uk - translation kinetic energy

Ur - rotational kinetic energy

I is the moment of inertia of the solid cylinder

⇒ 1/2 mv² + 1/2 Iω²

⇒ 1/2 mv² + 1/2 [1/2 m r² * (v/r)²]

⇒ 1/2* 5 * (2)² + 1/2 [1/2* 5 *(0.3)² * (2/0.3)²]

⇒ 10 + 1/2*1/2*5* (0.3)²* 4 / (0.3)²

⇒ 10 + 5 = 15 J

Thus, the total kinetic energy is 15 J.

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The asteroids are moved by Jupiter under the influence of (b) orbital resonances.

What are asteroids ?

Small, stony objects called asteroids orbit the Sun. Asteroids, sometimes known as minor planets, are rocky, airless debris from the early stages of the solar system's creation, which occurred around 4.6 billion years ago.

When two satellites' orbital periods are related by integer relationships, they can exert gravitational pull on one another and change the eccentricity of their orbits, resulting in an orbital resonance. Io, Europa, and Ganymede are the three inner moons of planet Jupiter. They are locked in a 4:2:1 orbital resonance, which means they are playing the same note in different octaves. The tones that Callisto and Ganymede produce are almost an octave and a minor third apart because they are almost in a 12:5 resonance.

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Air in an ideal Diesel cycle is compressed from 4 L to 0.25 L, and then it expands during the constant pressure heat addition process to 0.50 L. Under cold air standard conditions, the thermal efficiency of this cycle is 65.2%.

For an air standard engine with γ = 1.4, compression ratio r and fuel cut off ratio rc where r = V1/V2

and rc = V3/V2 and V1 = 4l, V2 = 0.25l and V3 = 0.50l

The efficiency (n) of diesel cycle is ----

n = 1 - [1 / r^(γ - 1)] * (rc^γ -1) / γ(rc - 1)

n = 1 - [1/(4/0.25)^(1.4-1)] * (0.50/0.25)^1.4 - 1 / 1.4 [(0.50/0.25) -1 ]

n = 1 - [1/3.03] * [2.63 - 1] / 1.4x1

n = 0.652

n% = 65.2%

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This situation appears in physics problems because of the negative charge, an inward-facing radial electric field is produced.

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The period measured by student b using analog wristwatch is more accurate because of less percentage of error.

Accuracy is the capacity of an instrument to measure the precise value. In other words, it refers to how closely the measured value resembles a reference or genuine value. Small readings can be taken to increase accuracy. The calculation's error is decreased by the little reading.

Given that:

period of oscillation, t = 1. 55 s.

an average period for the 5 oscillations obtained by student a: t = 1. 25 s.

average period for the 5 oscillations  obtained by student b: t = 1. 6 s

Hence, error percentage of student a = (1.55-1.25)/1.55 × 100% = 19.35%

error percentage of student b = (1.60-1.55)/1.60  × 100%  = 3.22%

Hence,  period measured by student b is more accurate because of less percentage of error.

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The correct answer is b.

The given statement is true for sufficiently short distances.

At the end of t seconds, the distance travelled by a freely falling object with zero initial velocity is [tex]s=ut+1/2 gt^{2}[/tex]

where s is the displacement, t is the time, u is the initial velocity and g is the acceleration due to gravity.

Here, when the object is under free fall, its initial velocity, [tex]u=0 m/s[/tex]

Gravity continuously accelerates an object (increases its velocity) during free fall until it reaches terminal velocity. In particular, for every second that passes, gravity accelerates a falling object by 9.8  (m/s). (Acceleration is measured in meters per second squared, or m/s2, whereas velocity is measured in m/s.)

It is only sometimes true that an object falling freely needs to travel a greater distance in one second than it did in all the preceding seconds. However, if the object is falling under the influence of gravity for very short distances, the above claim can be approximately true.

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It is erroneous to claim that mirrors are not used by microscopes to magnify objects.

A microscopy is a tool that may be used to examine tiny things, including cells. By at least one lens, the microscope magnifies the picture of an item. This lens twists light in a way that causes it to look as though an item is larger than the amount is.

The microscopy, which is the most popular and the first to be created, employs lenses to diffract visible light that has gone through a thinly sheared material to create a viewable picture.

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Yes if there is no energy losses, the pulse will propagate along the rope without changing its original shape.

In every rope, the least dense rope has the largest wavelength. Crossing a barrier does not change a wave's frequency. If a wave in a less dense rope is traveling toward a border with a more dense rope, the reflected pulse will become inverted. The pulse will travel the length of the rope without altering its original shape if there are no energy losses.After reflecting off the fixed end, the pulse is inverted. To put it another way, a pulse with an upward displacement will reflect off the end and return with a downward displacement. When the medium's end is fixed, this characteristic of inversion will always be seen. When a wave or pulse moving through one medium encounters the boundary of another, a portion of the incident pulse is reflected off the border and a portion is transmitted over the boundary.

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A galaxy's halo is a large, generally spherical area that surrounds the disk.

Solution b is accurate.

An extended, approximately spherical component of a galaxy that extends beyond the primary, visible component is called a galactic halo. The halo is made up of several distinctive galaxy parts, including: the halo of a star. a galaxy's corona (hot gas, i.e. a plasma)

The term "halo" refers to a ring of light that seems to surround the sun or moon and is caused by the refraction or reflection of light by atmospheric ice particles.

Globular clusters and other aging stars can be found in the galactic halo, a region of the galaxy that extends far above and below the galactic disk. - Roughly round; somewhat flattened. - Only includes old stars. - is free of gas and dust.

Thus halo galaxy is a large, roughly spherical region surrounding the disk (option B is correct)

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To establish mechanical equilibrium, the fulcrum must be placed 3.27 m away from the 250 N weight.

The position of the fulcrum from the 250 N weight is determined by applying the principle of moment as shown below.

let the position of the fulcrum = d

The position of the 250 N from the fulcrum must be greater than the center of the beam since 300 N is heavier than 250 N.

----------------------------------Δ--------------------------------

↓                                     d                                      ↓

250 N                                                                    300 N    

the position of the 250 N weight from the fulcrum = d

the position of the 300 N weight from the fulcrum = 6 m - d

take moment about the pivot;

sum of the antic lock wise moment = sum of the clockwise moment

250 ( d ) = 300 ( 6 - d )

250d = 1,800 - 300d

550d = 1,800

d = 1,800 / 550

d = 3.27 m                              

Thus, the position of the fulcrum from 250 N depends on the length of the beam and the weight hanging at the other end.

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The magnetic field of the solenoid will be 30.79 T.

Magnetic field strength is a quantitative measure of the strength or weakness of a magnetic field.

Length of solenoid, L = 1.5 cm = 0.015 m

Radius of solenoid, r = 0.65 cm = 0.0065 m

Number of turns, N = 49 turns

Current, I = 1.45 A

Magnetic field, B, can be calculated as B = (N*r*I) /L

B = (49 * 0.0065 * 1.45)/0.015

B =  30.79 T

The magnitude of the magnetic field inside the solenoid is 30.79 T.

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When a satellite revolves around the Earth at a speed of v2=31300 m/s, there is no torque on the Earth.

What does the term "torque" mean?

A torque is an angular force that tends to generate rotation along an axis, which could be a fixed point or the center of mass. Torque can also be conceived of as a spinning object's capacity to overcome turning resistance, such as a gear or a shaft.

In vehicles, what does torque mean?

When used to describe internal combustion engines or electric motors, torque refers to the force acting on the driving shaft. Torque is measured in newton-meters or pounds-feet (lb-ft) (Nm). Engine power is determined by the relationship between torque and engine speed (rpm).

Briefing:

mv1r1=mv2r2

2500*6260=v2*500

v2=31300m/s

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