Physics final actual math problems

How many atoms are there in a 5.1-g copper coin?

4.8 × 10²² atoms

"Room temperature" is often taken to be 68 ∘F.

1. What is this on the celcius scale?

2. The temperatyre of the filiment in a lightbuld is about 2300° C. What is this on the Farenheit Scale?

F° = (C°(9/5)) + 32

1. T = 20°C

2. T= 4200 °F

17° below 0 on the celcius scale is what farenheit temp?

F° = (C°(9/5)) + 32

T= 1.4 °F

17° below 0 on the farenheit scale is what celcius temp?

F° = (C°(9/5)) + 32

-27 °C

The Eiffel Tower is built of wrought iron approximately 300 m tall. Assume the coefficient of thermal expansion of wrought iron is 12 ×10⁻⁶1/C∘

Estimate how much its height changes between January (average temperature of 2 ∘C) and July (average temperature of 25 ∘C). Ignore the angles of the iron beams and treat the tower as a vertical beam.
ΔL = μ(L_o)(ΔT)

Δl = 8.3 × 10^-2 m

A concrete highway is built of slabs 10 m long (15 ∘C).

How wide should the expansion cracks between the slabs be (at 15 ∘C) to prevent buckling if the range of temperature is -30∘C to +54 ∘C?

ΔL=μ(L_o)(ΔT)

4.7 × 10^-3 m

Super Invar, an alloy of iron and nickel, is a strong material with a very low coefficient of thermal expansion (0.20× 10−6 C∘). A 1.8-m-long tabletop made of this alloy is used for sensitive laser measurements where extremely high tolerances are required.

1. How much will this alloy table expand along its length if the temperature increases 6.5 C∘

2. How much will a 1.8-m-long table made of steel expand along its length if the temperature increases 6.5 C∘?

ΔL=μ(L_o)(ΔT)

1. 2.x10^-6 m

2. 1.4 × 10^-4 m

An aluminum sphere is 8.50 cm in diameter.

What will be its % change in volume if it is heated from 30∘C to 150 ∘C?

volume = 4/3 (pi)(r³)

aluminmum = 7.5 × 10^-6 (1/C^o)

ΔV=μ(V_o)(ΔT)

0.9%

Absolute zero is what temperature on the Fahrenheit scale (-273.15°C.)?

F° = (C°(9/5)) + 32

-460°F

If 2.96 m3 of a gas initially at STP is placed under a pressure of 2.35 atm , the temperature of the gas rises to 35.7 ∘C.

What is the volume?

(p₁v₁)/T₁ = (p₂v₂)/T₂

_{STP = 273.15 K}

1.42 m³

If 18.21 mol of helium gas is at 13.7 ∘C and a gauge pressure of 0.395 atm .

1. Calculate the volume of the helium gas under these conditions.

2. Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.11 atm .

Celcius to Kelvin »∘C + 273 = K

P_abs=P_gague+P_atm

V=(nRT)/(P_abs)

1. 0.307 m³

2. -56.2 °C

A storage tank at STP contains 23.1 kg of nitrogen (N₂).

1. What is the volume of the tank?

2. What is the pressure if an additional 25.3 kg of nitrogen is added without changing the temperature?

2.1 atm

Calculate the number of molecules/m3 in an ideal gas at STP.

2.69×10²⁵ moleclues/m³

Calculate the rms speed of helium atoms near the surface of the Sun at a temperature of about 7000 K.

6600 m/s

To what temperature will 7900 J of heat raise 3.0 kg of water that is initially at 13.0 ∘C? The specific heat of water is 4186 J/kg⋅C∘.

13.6°C

How much heat (in joules) is required to raise the temperature of 38.0 kg of water from 16 ∘C to 85 ∘C? The specific heat of water is 4186 J/kg⋅C∘

1.1 × 10⁷ J

A water heater can generate 36,000 kJ/h. The specific heat of water is 4186 J/kg⋅C∘. How much water can it heat from 12 ∘C to 44 ∘C per hour?

270 kg/h

An automobile cooling system holds 16 L of water. The specific heat of water is 4186 J/kg⋅C∘. How much heat does it absorb if its temperature rises from 17 ∘C to 83 ∘C?

4.4 × 10⁶ J

What is the specific heat of a substance if 120 kJ of heat is needed to raise 4.1 kg of the substance from 18.0 ∘C to 37.2 ∘C?

1500 J/kg( C )

The value of specific heat for copper is 390 J/kg⋅C∘, for aluminun is 900 J/kg⋅C∘, and for water is 4186 J/kg⋅C∘. What will be the equilibrium temperature when a 255 g block of copper at 235 ∘C is placed in a 135 g aluminum calorimeter cup containing 815 g of water at 16.0 ∘C?

22 Celcius

A 0.40-kg iron horseshoe, just forged and very hot (Figure 1), is dropped into 1.45 L of water in a 0.32-kg iron pot initially at 20.0∘C. The value of specific heat for iron is 450 J/kg⋅C∘ , and for water is 4186 J/kg⋅C∘ If the final equilibrium temperature is 25.0 ∘C, Determine the initial temperature of the hot horseshoe

200 C

When a 270-g piece of iron at 180 ∘C is placed in a 95-g aluminum calorimeter cup containing 250 g of liquid at 10∘C, the final temperature is observed to be 39 ∘C. The value of specific heat for iron is 450 J/kg⋅C∘, and for aluminum is 900 J/kg⋅C∘. Determine the specific heat of the liquid.

2000 (J)/(kg)(C)

How much heat is needed to melt 13.50 kg of silver that is initially at 19 ∘C? The melting point of silver is 961∘C, the heat of fusion is 88 kJ/kg, the specific heat is 230 J/kg⋅C∘.

4.1 × 10⁶ J

Monochromatic light falling on two slits 0.016 mm apart produces the fifth-order bright fringe at an 8.8 ∘ angle.What is the wavelength of the light used?

4.9×10⁻⁷ m

The third-order bright fringe of 590 nm light is observed at an angle of 29 ∘ when the light falls on two narrow slits. How far apart are the slits?

3.7×10⁻⁶ m

If 710-nm and 640-nm light passes through two slits 0.64 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.5 m away?

3.3×10⁻⁴ m

Light of wavelength 720 nm falls on two slits and produces an interference pattern in which the third-order bright red fringe is 37 mm from the central fringe on a screen 1.4 m away. What is the separation of the two slits?

8.2×10⁻⁵ m

A parallel beam of light from a He-Ne laser, with a wavelength 633 nm, falls on two very narrow slits 0.058 mm apart. How far apart are the fringes in the center of the pattern on a screen 4.3 m away?

4.7×10⁻² m

In a double-slit experiment, the third-order maximum for light of wavelength 490 nm is located 18 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 670 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?

16 mm

Monochromatic light falls on a slit that is 2.30×10⁻³ mm wide.If the angle between the first dark fringes on either side of the central maximum is 29.0 ∘ (dark fringe to dark fringe), what is the wavelength of the light used?

576 nm

When blue light of wavelength 470 nm falls on a single slit, the first dark bands on either side of center are separated by 53.0 ∘.Determine the width of the slit.

1.05×10⁻⁶ m

A single slit 1.2 mm wide is illuminated by 440-nm light.What is the width of the central maximum (in cm ) in the diffraction pattern on a screen 7.0 m away?

0.51 cm

How wide is the central diffraction peak on a screen 2.50 m behind a 0.0328-mm-wide slit illuminated by 588-nm light?

8.96×10⁻² m

At what angle will 410-nm light produce a second-order maximum when falling on a grating whose slits are 1.05×10⁻³ cm apart?

4.48 Deg

A grating that has 3200 slits per cm produces a third-order fringe at a 24.0 ∘ angle. What wavelength of light is being used?

4.2×10⁻⁷ m

A grating has 7100 slits/cm. How many full spectral orders can be seen (400 to 700 nm) when it is illuminated by white light?

2 full spectral orders

How many slits per centimeter does a grating have if the third-order occurs at an 14.0 ∘ angle for 560-nm light?

1440 slits/cm

White light containing wavelengths from 410 nm to 750 nm falls on a grating with 7200 slits/cm. How wide is the first-order spectrum on a screen 3.30 m away?

1.1 m