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3 years ago

A block of mass m begins at rest at the top of a ramp at elevation h with whatever pe is associated with that height.

2 answers:

8 0

<span>PE = mass * height * g = 87.60 J

Frictional force = m * g * sin theta * uk = 4.7 kg * 9.81 m/sec^2 * sin 36.87 * 0.3 = 8.299 N

Work done by friction = force * distance = 41.50 J

Remaining energy to be converted to KE = 87.60 J - 41.50 J = 41.10 J</span>hope it helps

Darina [25.2K]3 years ago

8 0

Answer:

The PE associated with that height is given as, m×g×h

Explanation:

Potential energy (PE) is the energy possessed by an object when at rest. Its opposite is the kinetic energy (KE). When an object is at a certain height, it would possess potential energy because initially it is at rest. Also the value of the energy is determined by its mass, height and the force of gravity acting on it at that height.

So, the potential energy (PE) = mass× height× value of the gravitational force

= m× g× h

Its unit is Joules. The potential energy of the mass would be converted to kinetic energy when it is in motion.

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The following three questions refer to a situation in which a driver is in a car that crashes into a solid wall. The car comes t

Andreas93 [3]

Answer:

1) p₀ = 45000 N / s , p₀ '= 1800 , b) I = -45000 N s , I = 1800 Ns

Explanation:

Impulse equals the change in momentum

I = Δp

1) the initial moment of the car

p₀ = M v

p₀ = 1500 30

p₀ = 45000 N / s

the change at the moment is

Δp = 45000

because the end the car is stopped

moment of the person

P₀ ’= m v

p₀ '= 60 30

p₀ '= 1800

D₀ '= 1800

2) of the momentum change impulse ratio

car

I = Δp

I = -45000 N s

person

I = Δpo '

I = 1800 Ns

3) the object that give the momentum to stop the wall motoring

The person is stopped by the impulse given by the car

a) This area is the one that absorbs most of the vehicle impulse

be) If using a safety painter, the time during which the greater force will act, therefore the lessons decrease

c) The air bag helps reduction in the speed of the person relatively quickly.

6 0

3 years ago

The electric current in a copper wire is composed of what

Tanzania [10]

Answer:

A copper wire current consists of electrons appropriately called conduction electrons.

Explanation:

This answer came from quizlet.com. I hope that this helps you and good luck!

8 0

2 years ago

A heat engine with 0.300 mol of a monatomic ideal gas initially fills a 1000 cm3 cylinder at 500 K . The gas goes through the fo

LuckyWell [14K]

Complete Question:

A heat engine with 0.300 mol of a monatomic ideal gas initially fills a 1000 cm3 cylinder at 500 K . The gas goes through the following closed cycle: - Isothermal expansion to 5000 cm3. - Isochoric cooling to 400 K . - Isothermal compression to 1000 cm3. - Isochoric heating to 500 K .

a) what is the work for one cycle

b) what is the thermal efficiency

Answer:

a) Work done for 1 cycle = 402.13

b) Thermal efficiency = 20%

Explanation:

Number of moles, n = 0.300 mol

Initial Volume, V₁ = 1000 cm³

Temperature, T = 500 K

Isothermal expansion to 5000 cm³

Final volume, V₂ = 5000 cm³

R = 8.314 J/ mol.K

Work done, W = nRT ln(V₂/V₁)

W = (0.3 * 8.314 * 500) * ln(5000/1000)

W = 1247.1 * ln5

W₁ = 2007.13 J

Isochoric cooling

In an Isochoric process, volume is constant i.e. V₂ = V₁ = V

W = nRT ln(V/V)

But ln(V/V) = ln 1 = 0

Work done, W₂ = 0 Joules

Isothermal Compression to 1000 cm³

V₂ = 1000 cm³

V₁ = 5000 cm³

W = nRT ln(V₂/V₁)

W = 0.3 * 8.314 * 400 ln(1000/5000)

W₃ = -1605 J

Isochoric heating to 500 K

Since there is no change in volume, no work is done

W₄ = 0 J

a) Work done for 1 cycle

W = W₁ + W₂ + W₃ + W₄

W = 2007.13 + 0 + 0 -1605+0

W = 402.13 Joules

b) Thermal efficiency

Thermal efficiency = (Net workdone for 1 cycle)/(Heat absorbed)

Heat absorbed = Work done due to thermal expansion = 2007.13 J

Thermal efficiency = 402.13/2007.13

Thermal efficiency = 0.2

Thermal efficiency = 0.2 * 100% = 20 %

3 0

3 years ago

The wavelength of light that has a frequency of 1.20 × 1013 s-1 is ________ m.

klio [65]

The relationship between frequency and wavelength for an electromagnetic wave is
$c=f \lambda$
where
f is the frequency
$\lambda$ is the wavelength
$c=3 \cdot 10^8 m/s$ is the speed of light.

For the light in our problem, the frequency is $f=1.20 \cdot 10^{13} s^{-1}$ , so its wavelength is (re-arranging the previous formula)
$\lambda= \frac{c}{f}= \frac{3 \cdot 10^8 m/s}{1.20 \cdot 10^{13} s^{-1}}= 2.5 \cdot 10^{-5}m$

8 0

3 years ago

You run<br> completely around a 400m track in<br> 80s. What was your average velocity?

dalvyx [7]

Answer:

V=?

S=400m

t=80s

V=S/t

V=400/80

V=5m/sec

6 0

3 years ago