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Svetradugi [14.3K]

3 years ago

14

A glass of water sits on a scale. The scale reads 4.78 N. A steel bolt weighs 2.07 N. The density of steel is 7.86 g/cm3. We tie

the bolt to a string and lower the bolt into the glass of water so that the bolt is fully submerged in the water but is not touching the bottom or side of the glass.

1 answer:

miv72 [106K]3 years ago

4 0

Answer:

The weight of water weight is 5.043 N.

Explanation:

Given that,

Force = 4.78 N

Weight of steel bolt = 2.07 N

Density of steel = 7.86 g/cm³

Suppose determine how much does the glass of water weight.

We need to calculate the volume of bolt

Using formula of density

$\rho_{b}=\dfrac{m}{V}$

$V=\dfrac{m}{\rho_{b}}$

Put the value into the formula

$V=\dfrac{2.07}{9.8\times7860}$

$V=2.6873\times10^{-5}\ m^3$

We need to calculate the force on bolt

Using buoyant force

$F=\rho gV$

Put the value into the formula

$F=1000\times9.8\times2.6873\times10^{-5}$

$F=0.263\ N$

We need to calculate the new weight of glass of water

Using formula for weight of glass of water

$W'_{w}=W_{w}+F_{b}$

Put the value into the formula

$W=4.78+0.263$

$W=5.043\ N$

Hence, The weight of water weight is 5.043 N.

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3.27 moles of an ideal gas in a 50.0 L tank has a pressure of 171000 Pa. What is the temperature of the gas? (Unit=degrees C)

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The temperature of the gas is 41.3 °C.

Answer:

The temperature of the gas is 41.3 °C.

Explanation:

So on combining the Boyle's and Charles law, we get the ideal law of gas that is PV=nRT. Here P is the pressure, V is the volume, n is the number of moles, R is gas constant and T is the temperature. The SI unit of pressure is atm. So we need to convert 1 Pa to 1 atm, that is 1 Pa = 9.86923× $10^{-6}$ atm. Thus, 171000 Pa = 1.6876 atm.

We know that the gas constant R = 0.0821 atmLMol–¹K-¹. Then the volume of the gas is given as 50 L and moles are given as 3.27 moles.

Then substituting all the values in ideal gas equation ,we get

1.6876×50=3.27×0.0821×T

Temperature = $\frac{84.38}{0.268467} =314.3 K$

So the temperature is obtained to be 314.3 K. As 0°C = 273 K,

Then 314.3 K = 314.3-273 °C=41.3 °C.

Thus, the temperature is 41.3 °C.

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3 years ago

Two long, straight wires are separated by a distance of 9.15 cm . One wire carries a current of 2.79 A , the other carries a cur

Dafna1 [17]

Answer:

The force is the same

Explanation:

The force per meter exerted between two wires carrying a current is given by the formula

$\frac{F}{L}=\frac{\mu_0 I_1 I_2}{2\pi r}$

where

$\mu_0$ is the vacuum permeability

$I_1$ is the current in the 1st wire

$I_2$ is the current in the 2nd wire

r is the separation between the wires

In this problem

$I_1=2.79 A\\I_2=4.36 A\\r = 9.15 cm = 0.0915 m$

Substituting, we find the force per unit length on the two wires:

$\frac{F}{L}=\frac{(4\pi \cdot 10^{-7})(2.79)(4.36)}{2\pi (0.0915)}=2.66\cdot 10^{-5}N$

However, the formula is the same for the two wires: this means that the force per meter exerted on the two wires is the same.

The same conclusion comes out from Newton's third law of motion, which states that when an object A exerts a force on an object B, then object B exerts an equal and opposite force on object A (action-reaction). If we apply the law to this situation, we see that the force exerted by wire 1 on wire 2 is the same as the force exerted by wire 2 on wire 1 (however the direction is opposite).

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3 years ago

How is the density of ice compare with the density of water? explain to me pplz

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Lower. Water expands on lower temperatures, meaning less molecules in 1 m3, thus making it less dense

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3 years ago

If a ball is thrown straight up into the air with an initial velocity of 65 ft/s, its height in feet after t seconds is given by

fgiga [73]

Answer:

a) $v_{1}=\frac{(62.5-66)ft}{(2.5-2)s}=-7ft/s$

$v_{2}=\frac{(65.94-66)ft}{(2.1-2)s}=-0.6ft/s$

$v_{3}=\frac{(66.0084-66)ft}{(2.01-2)s}=0.84ft/s$

$v_{4}=\frac{(66.001-66)ft}{(2.001-2)s}=1ft/s$

b) $v=65-32(2)=1ft/s$

Explanation:

From the exercise we got the ball's equation of position:

$y=65t-16t^{2}$

a) To find the average velocity at the given time we need to use the following formula:

$v=\frac{y_{2}-y_{1} }{t_{2}-t_{1} }$

Being said that, we need to find the ball's position at t=2, t=2.5, t=2.1, t=2.01, t=2.001

$y_{t=2}=65(2)-16(2)^{2} =66ft$

$y_{t=2.5}=65(2.5)-16(2.5)^{2} =62.5ft$

$v_{1}=\frac{(62.5-66)ft}{(2.5-2)s}=-7ft/s$

--

$y_{t=2.1}=65(2.1)-16(2.1)^{2} =65.94ft$

$v_{2}=\frac{(65.94-66)ft}{(2.1-2)s}=-0.6ft/s$

--

$y_{t=2.01}=65(2.01)-16(2.01)^{2} =66.0084ft$

$v_{3}=\frac{(66.0084-66)ft}{(2.01-2)s}=0.84ft/s$

--

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$v_{4}=\frac{(66.001-66)ft}{(2.001-2)s}=1ft/s$

b) To find the instantaneous velocity we need to derivate the equation

$v=\frac{df}{dt}=65-32t$

$v=65-32(2)=1ft/s$

7 0

3 years ago

How do I calculate speed, velocity, and acceleration? I need the formulas too

vodomira [7]

Speed is the secular unit, which means it only measures "how fast it goes."
$speed= \frac{distance}{time}$
Velocity is a victory unit, which means it measures "both how fast it goes AND the direction."
$velocity= displacement/time$
Acceleration is the change of velocity over time.
$acceleration = \frac{change in velocity}{time}$

5 0

3 years ago