An object of mass m is hanging by a string from the ceiling of an elevator. The elevator is moving down at constant speed. What is the tension of the string?

A. Zero
B. Equal to mg
C. Less than mg
D. Greater than mg​

Explanation:

(a) A machine is a device by which we can either overcome a large resistive force at some point by applying a small force at a convenient point and in a desired direction or by which we can obtain a gain in the speed.

(b) An ideal machine is a machine whose parts are weightless and frictionless so that which there is no dissipation of energy in any manner. Its efficiency is 100%, i.e. the work output is equal to work input.

. Power

Patintero

, also known as harangang-taga or tubigan, (Intl. Translate: Escape from the hell or Block the runner) is a traditional Filipino children's game. Along with tumbang preso, it is one of the most popular outdoor games played by children in the Philippines.[1]

is an ultramarathon trail race held in Frozen Head State Park near Wartburg, Tennessee. If runners complete 60 miles (97 km) this is known as a "fun run." The full course is about 100 miles (160 km). The race is limited to a 60-hour period and takes place in late March or early April of each year.

Answer:

the answer is 3,888.7

Explanation:

Hope this answer helped!:)

Answer:

Approximately [tex]2\; \rm s[/tex], assuming that the floor of this parking lot is level, [tex]\mu_{\rm k} = 0.60[/tex], and [tex]g = 9.81\; \rm m\cdot s^{-2}[/tex].

Explanation:

Let [tex]m[/tex] denote the mass of this vehicle. Weight of this vehicle: [tex]m\, g[/tex].

If the floor of this parking lot is level, the normal force on this vehicle would be equal to its weight: [tex]N = m \, g[/tex].

Given that [tex]\mu_{\rm k}[/tex], the kinetic friction between this vehicle and the ground would be consistently [tex]\mu_{\rm k} \, N = \mu_{\rm k} \, m \, g[/tex] until the vehicle comes to a stop.

Assuming that all forces on this vehicle other than friction are balanced. The net force of this vehicle during braking would be [tex](-\mu_{\rm k} \, m \, g)[/tex] (negative because this force is opposite to the direction of the motion.)

By Newton's second law of motion, the acceleration of this vehicle would be:

[tex]\begin{aligned}a &= \frac{F_\text{net}}{m} \\ &= \frac{-\mu_{\rm k} \, m \, g}{m} \\ &= -\mu_{\rm k}\, g \\ &= -0.60 \times 9.81\; \rm m\cdot s^{-2} \\ &= -5.886\; \rm m\cdot s^{-2}\end{aligned}[/tex].

In other words, braking would reduce the velocity of this vehicle by a constant [tex]5.886\; \rm m\cdot s^{-1}[/tex] every second until the vehicle comes to a stop. Calculate the time it would take to reduce the velocity of this vehicle from [tex]v_{0} = 12\; \rm m\cdot s^{-1}[/tex] to [tex]v_{1} = 0\; \rm m\cdot s^{-1}[/tex]:

[tex]\begin{aligned}t &= \frac{v_{1} - v_{0}}{a} \\ &= \frac{0\; \rm m\cdot s^{-1} - 12\; \rm m\cdot s^{-1}}{-5.886\; \rm m \cdot s^{-2}} \\ &\approx 2.0\; \rm s \end{aligned}[/tex].

Acceleration is the slope of the velocity-time graph. Since the acceleration here is constant, the velocity-time graph of this vehicle would be a line with a negative slope.

Answer:

By applying the definition of torques ( [tex]\vec \tau = \vec r \times \vec F[/tex] ) and them remembering a few tricks.

Namely: if you wrap your RIGHT hand fingers around something and stick your thumb out, the direction your finger wraps gives you the verse of rotation and the thumb the orientation of the torque. Bottom force (4N) will give a counterclockwise rotation, torque is pointing up; top force (3N) will give a clockwise rotation and its torque its pointing down (read up and down as if the sheet the image is printed on is on your table).

In terms of magnitude the trick is easy: You want to multiply the intensity of the force (3N and 4N) by the distance between the point and the line the force it is applied to (that is, you don't care about the length of r itself, but the distance at a right angle, which is 0.9 and 0.8m respectively.

At this point, assuming "upwards" (relative to the plane of the sheet that is) torques positive, the 3N force gives you a torque of [tex]- 3N \times 0.9m = - 2.7N\cdot m[/tex] and the 4N force provides [tex]+4N\times 0.8 m = +3.2 N\cdot m[/tex]

Answer:

40 volts

Explanation:

Use the equation [tex]V=IR[/tex]

[tex]V=(4)(10)[/tex]

[tex]V=40[/tex]

Answer:

Explanation:

F = GMm/d²

d = √(GMm/F)

d = √(6.674e-11(8.68e25)(6.59e19) / 2.28e19)

d = 1.29398e8 = 1.29 x 10^8 m  center to center

Answer:

1.29 x 10^8 m  apart

Explanation:

Works in Acellus!

Answer:

The Aluminum

Explanation:

With a larger specific heat, water requires more heat to raise its temperature by a temperature degree.

In this system, with equal masses of water and aluminum, the heat moving from the aluminum lowering its temperature by one degree is not sufficient to raise the water temperature by one degree.

Answer:

According Lisa, both the ball and the balloon have the same forward velocity of Vx.

(D) is correct

The self-inductance of the solenoid is 8.25 mH.

The given parameters;

The area of the solenoid is calculated as follows;

[tex]A = \pi r^2\\\\A = \pi \times (0.02)^2\\\\A = 0.00125 \ m^2[/tex]

The self-inductance of the solenoid is calculated as follows;

[tex]L = \frac{\mu_o N^2 A }{l} \\\\L = \frac{(4\pi \times 10^{-7}) \times 1700^2 \times 0.00125}{0.55} \\\\L = 0.00825 \ H\\\\L = 8.25\ mH[/tex]

Thus, the self-inductance of the solenoid is 8.25 mH.

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Answer:

Explanation:

The deflection of a charged particle by a magnetic field is proportional to its electric charge and to its velocity.   The deflection is also inversely proportional to its mass.   So given a proton and an electron going at the same velocity in a magnetic field and having equal (but opposite) electric charge the electron will deflect much more since the ratio of the masses is 1836.

Answer:

Summertime

Explanation:

the sun never sets south of the Antarctic circle in the summertime.

The mechanical advantage of ramp A is greater than others and it will require the least force to move the load to greater distance.

The mechanical advantage of the ramp is calculated as follows;

[tex]M.A = \frac{L}{h}[/tex]

The mechanical advantage of the ramp B, C, D and E is calculated as;

[tex]M.A = \frac{L}{h} \\\\[/tex]

The mechanical advantage of the ramp A is calculated as follows;

[tex]M.A = \frac{2L}{h} \\\\M.A = 2(\frac{L}{h} )[/tex]

Since the length of the ramp A is greater than other ramps, the mechanical advantage will be greater and it will require the least force to move the load to greater distance.

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Answer:b

Explanation:

-29.4 m/s

The velocity of the ball dropped from 80 m if it reaches the ground within 3 seconds is 26.6 m/s. If it is in midway within this time, then the velocity will be 29.4 m/s.

Velocity of a moving object is the measure of its distance travelled per unit time. Velocity is a vector quantity having both magnitude and direction. Acceleration is the rate of change in velocity.

Given that, height of the building = 80 m

the ball is moving downwards by acceleration due to gravity g = 9.8 m/s².

Then after 3 seconds, the velocity of the ball is calculated as follows:

velocity = acceleration × time

v = 9.8 m/s²  × 3 s = -29.4 m/s

If the ball reaches the ground within the time of 3 s, then, the velocity is:

v = 80 m/3s = 26.6 m/s.

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Answer:

A saturated vapour is one that is in balance with its own liquid. Space is considered to be unsaturated if it contains fewer vapours than the maximum amount it can retain at a given temperature. Saturated vapour pressure is unaffected by volume, although it rises as temperature rises.

Explanation:

Answer:

In this problem basically we will use directions to find displacement and distance .

(Keep in mind that displacement is vector while distance is scalar quantity)  

And then we will use displacement and distance to find average velocity and average speed.

Explanation:

Answer:

5m

Explanation:

x=?

[tex]sin30^{0} =\frac{x}{10}[/tex]

[tex]x=10sin30^{0} =10(0.5)=5[/tex]

Hope this helps

Answer:

Papillae is correct

Explanation:

hope it helps you

Answer:

Papillae is the correct answer of this question

Answer:

Explanation:

F = ma

a = F/m

a = mBg / (mB + mA)

a = 3.5(9.8)/(3.5 + 3.4)

a = 4.971014...

a = 5.0 m/s²

If you want to use individual Free Body Diagrams

mass A will have downward weight and upward normal forces equal at mAg

and a horizontal force of string tension T

F = ma

T = mAa

mass B will have a downward force of mBg and an upward force of T

mBg - T = mBa

substitute for T

mBg - mAa = mBa

mBg = a(mB + mA)

a = mBg / (mB + mA)   which is identical to the above answer.

Answer:

velocity is a vector quantity

Explanation:

velocity is a vector quantity because it has a mass and a direction

Answer:

not sure i need points

Explanation:

Answer:

The 7 states of matter are solid, loquid, gas, fermionoc condensate, quark gluton plasm, bose einetein condensate amd ionised plasm but its usually only 3 they teach you

Answer:

7

Explanation:

solid, liquid,gas,fermionoc condensate,quark glutton plasm,bose einetein condensate amd ionised plasm.

(a) The height of the roller coaster at 120,000 potential energy is 122.45 m.

(b) The velocity of the roller coaster at 0 J kinetic energy is 0.

(c) The height of the roller coaster at 60,000 potential energy is 61.23 m.

(d) The velocity of the roller coaster at 60,000 J kinetic energy is 34.64 m/s.

(e) The height of the roller coaster at 40,000 potential energy is 40.82 m.

(f) The velocity of the roller coaster at 80,000 J kinetic energy is 40 m/s.

The given parameters:

When the kinetic energy = 0 and potential energy = 120,000 J

The height of the roller coaster is calculated as follows;

P.E = mgh

[tex]h = \frac{P.E}{mg}\\\\h = \frac{120,000}{100 \times 9.8} \\\\h = 122.45 \ m[/tex]

Since the kinetic energy = 0, the velocity of the roller coaster = 0

When the potential energy, P.E = 60,000 J, the kinetic energy, K.E is calculated as;

P.E + K.E = M.A

P.E + K.E = 120,000

60,000 + K.E = 120,000

K.E = 120,000 - 60,000

K.E = 60,000 J

The height of the roller coaster at 60,000 potential energy is calculated as follows;

[tex]h = \frac{P.E}{mg} \\\\h = \frac{60,000}{100 \times 9.8} \\\\h =61.23 \ m[/tex]

The velocity of the roller coaster at 60,000 J kinetic energy is calculated as follows;

[tex]K.E = \frac{1}{2} mv^2\\\\v^2 = \frac{2K.E}{m} \\\\v = \sqrt{ \frac{2K.E}{m}} \\\\v = \sqrt{ \frac{2\times 60,000}{100}}\\\\v = 34.64 \ m/s[/tex]

When the potential energy, P.E = 40,000 J, the kinetic energy, K.E is calculated as;

P.E + K.E = M.A

40,000 + K.E = 120,000

K.E = 120,000 - 40,000

K.E = 80,000

The height of the roller coaster at 40,000 potential energy is calculated as follows;

[tex]h = \frac{P.E}{mg} \\\\h = \frac{40,000}{100 \times 9.8} \\\\h = 40.82 \ m[/tex]

The velocity of the roller coaster at 80,000 J kinetic energy is calculated as follows;

[tex]v = \sqrt{\frac{2K.E}{m} } \\\\v = \sqrt{\frac{2\times 80,000}{100} } \\\\v = 40 \ m/s[/tex]

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The reason why a tiny 1.5 V cell can operate a calculator for a year, but would burn out in a few hours in a tiny robot is because the power demands of the calculator are way less than that of the tiny robot.

Cell capacity is measured by the amount of Amps and Amp Hour (A.H.) capacity for how long a battery can endure.

On the label or in the user's manual, batteries mention their reserve capability, which specifies the approximate amount of time they can operate between charges. You might notice a shorter or longer battery life if your circuit uses more or less power than this hypothetical circuit. Calculate the battery's entire capacity and divide it by the power of your circuit to see how long it can survive.

Load current, which is influenced by the power of the linked item, influences how quickly the battery's electrical capacity will be used up.

The reason the 1.5 V cell would operate the calculator for a year and yet die in a few hours with the robot is that the robot has a much higher load current than the calculator.

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The answer is C) kilogram

The SI unit in the given options is kilogram, the correct option is C.

The most common unit of measurement is the standard unit. These units are standardized, which means that everyone understands an object's size, weight, and other properties.

Standard Units of Measurement have fixed values that cannot be changed.

The International System of Units, abbreviated SI in all languages and sometimes pleonastically as the SI system, is the modern version of the metric system and the world's most widely used measurement system.

The SI is a coherent system of units of measurement that begins with seven base units: the second (symbol s, the unit of time), the metre (m, length), the kilogram (kg, mass), the ampere (A, electric current), and so on.

Thus, the correct option is C.

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Answer:

Convective heat transfer is the transfer of heat between two bodies by currents of moving gas or fluid. In free convection, air or water moves away from the heated body as the warm air or water rises and is replaced by a cooler parcel of air or water.

Explanation:

Hope this helped and have a great day

Heat can be transferred by convection through liquids. Heat travels where warmer liquid rises and cooler liquid sinks. An example of this can be heating up a pot of water. Hope this helps!

This problem is describing a pump from which water is discharged at 1 MPa and 165 °C and is asking for the specific volume and internal energy at those conditions, thus, we can use the steam tables for resolving this requirement.

First of all, we need to remember that water can be a saturated liquid, vapour or liquid-vapour mixture, and this is determined for the temperature and pressure it is at.

In this case, we find that at 165 °C the saturation pressure is about 0.6178 MPa; this means we are referring to a saturated liquid so that both the specific volume and internal energy can be simply read from the steam tables as vf and uf as follows:

[tex]v=0.001127\frac{m^3}{kg}\\\\u=761.67 \frac{kJ}{kg}[/tex]

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Answer:

Explanation:

In the vertical analysis assuming launch from ground level.

0 = 0 + (41.3sinθ)(5.1) + ½(-9.8)5.1²

(41.3sinθ)(5.1) = ½(9.8)5.1²

(41.3sinθ) = ½(9.8)5.1

sinθ = ½(9.8)5.1/41.3

sinθ = 0.60508...

θ = 37.235°

vx = 41.3cos37.235

vx = 32.881452...

vx = 32.9 m/s

Hi there!

We know that:

U (Gravitational Potential Energy) = mgh

Where:

g = acceleration due to gravity (m/s²)

m = mass (kg)

h = height/displacement (m)

Plug in the values:

U = 3 × 9.8 × 14 = 412 J