The first law of thermodynamics is just another form of the ____

A 720 kg roller-coaster starts off from Location A. Assuming friction does not impede the car's motion, what will be the change

vaieri [72.5K]

We know, Potential Energy = m * g * h
Here, mass & gravity would be same, but their height will change so it will be:

ΔU = U₂ - U₁
ΔU = mgh₂ - mgh₁
ΔU = mg (h₂ - h₁)

Hope this helps!

7 0

3 years ago

Read 2 more answers

Approximate the Sun as a uniform sphere of radius 6.96 X 108 m, rotating about its central axis with a period of 25.4 days. Supp

In-s [12.5K]

Answer:

T = 184 seconds

Explanation:

First in order to solve this, we need to know which is the expression to calculate the period. This is an exercise of angular velocity, so:

T = 2π/w

Where w: angular speed (in rad/s)

So, let's calculate first the innitial angular speed:

w = 2π/T

Converting days to seconds:

25.4 days * 24 h/day * 3600 s/h = 2,194,560 s

Then the angular speed:

w = 2π / 2,194,560 = 2.863x10^-6 rad/s

Now, the innitial angular momentum is:

I = (2/5)Mr² replacing data:

I = 2/5* (6.96x10^8)² * M = 1.94x10^17m² * M

so the initial angular momentum would be:

L = Iω = 2.863x10^-6 * 1.94x10^17 M

L = 5.55x10^11 m²/s * M = final angular momentum

Now the final I = 2/5Mr²

Final I = 2/5 * (6.37x10^6)² * M = 1.62x10^13m² * M

Then 5.55x10^11m²/s * M = 1.62x10^13m² * M * ω → M cancels

ω = 3.42x10^-2 rad/s

Then the new period

T = 2π/ω = 2*3.14 / 3.42x10^-2

T = 184 seconds

8 0

3 years ago

A 2-m long string is stretched between two supports with a tension that produces a wave speed equal to vw=50.00m/s. What are the

svetoff [14.1K]

Answer

given,

Length of the string, L = 2 m

speed of the wave , v = 50 m/s

string is stretched between two string

For the waves the nodes must be between the strings

the wavelength is given by

$\lambda = \dfrac{2L}{n}$

where n is the number of antinodes; n = 1,2,3,...

the frequency expression is given by

$f = n\dfrac{v}{2L}$

now, wavelength calculation

n = 1

$\lambda_1 = \dfrac{2\times 2}{1}$

λ₁ = 4 m

n = 2

$\lambda_2 = \dfrac{2\times 2}{2}$

λ₂ = 2 m

n =3

$\lambda_3 = \dfrac{2\times 2}{3}$

λ₃ = 1.333 m

now, frequency calculation

n = 1

$f = n\dfrac{v}{2L}$

$f_1 =1\times \dfrac{50}{2\times 2}$

f₁ = 12.5 Hz

n = 2

$f = n\dfrac{v}{2L}$

$f_2 =2\times \dfrac{50}{2\times 2}$

f₂= 25 Hz

n = 3

$f = n\dfrac{v}{2L}$

$f_3 =3\times \dfrac{50}{2\times 2}$

f₃ = 37.5 Hz

8 0

3 years ago

A weightlifter presses a 200 N weight 0.5 m over his head in 2 s. What is the power of the weightlifter

icang [17]

Answer:

50 watts

Explanation:

Applying,

Power (P) = Workdone (W)/Time(t)

But,

Work done (W) = Force (F)×distance(d)

Therefore,

P = Fd/t..................... Equation 1

Where P = power of the weightlifter, F = Force applied, d = distance, t = time.

From the question,

Given: F = 200 N, d = 0.5 m, t = 2 s

Substitute these values into equation 1

P = (200×0.5)/2

P = 100/2

P = 50 watts

7 0

2 years ago

Neritic Sediments are deposited on the ocean floor in a sorted manor. In which order are the sediments ordered moving from the s

BaLLatris [955]

B <span> of Earth’s surface is covered by water. Very little or no light penetrates beyond a few hundred feet in water</span>

6 0

3 years ago

The first law of thermodynamics is just another form of the _____.