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3 years ago

3. A cart at rest at the top of a roller coaster has 1000 J of

Physics

2 answers:

vovikov84 [41]3 years ago

5 0

Answer:

600J

Explanation:

Assuming no energy is lost and perfect transfers.

On the top of the first hill, $E_{k}+E_{p}=1000$ - however there is no Kinetic Energy so - $E_k = 0$

On the second hill, the total amount of energy is still the same (1000) - this time we have a smaller amount of potential energy. We can rearrange to get $E_k=1000-400$

wariber [46]3 years ago

4 0

Answer:

Explanation:

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madreJ [45]

Needs mass to be reasonably solvable, sorry

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4 years ago

Please help me on this position-time graph assignment!!!

saw5 [17]

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4 years ago

If the magnitude of vector A⃗ is less than the magnitude of vectorB⃗ , then the x component of A⃗ is less than the x component o

Mama L [17]

It’s true because..yeah

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3 years ago

I need help in my physics class and show me how it’s done

Korolek [52]

If we have the angle and magnitude of a vector A we can find its Cartesian components using the following formula

$A_x = |A|cos(\alpha)\\\\A_y = |A|sin(\alpha)$

Where | A | is the magnitude of the vector and $\alpha$ is the angle that it forms with the x axis in the opposite direction to the hands of the clock.

In this problem we know the value of Ax and Ay and we need the angle $\alpha$ .

Vector A is in the 4th quadrant

So:

$A_x = 6\\\\A_y = -6.5$

So:

$|A| = \sqrt{6^2 + (-6.5)^2}\\\\|A| = 8.846$

So:

$Ay = -6.5 = 8.846cos(\alpha)\\\\sin(\alpha) = \frac{-6.5}{8.846}\\\\sin(\alpha) = -0.7348\\\\\alpha = sin^{- 1}(- 0.7348)$

$\alpha$ = -47.28 ° +360° = 313 °

$\alpha$ = 313 °

Option 4.

4 0

3 years ago

Integrated Concepts A lightning bolt strikes a tree, moving 20.0 C of charge through a potential difference of 1.00×102 MV . (a)

vodka [1.7K]

Answer:

a) 2*10^9 J

b) 764.8 kg

Explanation:

Given that

Energy of charge, q = 20 C

Potential difference, ΔV = 1*10^2 MV = 1*10^2 * 10^6 V = 1*10^8 V

To find the energy dissipated, we use the formula

ΔU = qΔV

ΔU = 20 * 1*10^8

ΔU = 2*10^9 J

Change in temperature, ΔT = 100 - 15°

ΔT = 85° C

Change in energy, ΔU = 2*10^9 J

Specific heat of water, C = 4180 j./Kg.K

Latent heat of vaporization, L(v) = 2.26*10^6 J/Kg

Q1 = mcΔT

Q2 = mL(v)

Net energy needed, U = Q1 + Q2

U = mcΔT + mL(v)

U = m (cΔT + L(v))

m = U /[cΔT + L(v)]

Being that we have all the values, we then substitute

m = 2*10^9 / [(4180 * 85) + 2.26*10^6]

m = 2*10^9 / (3.553*10^5 + 2.26*10^6]

m = 2*10^9 / 2.615*10^6

m = 764.8 kg

Having 765 kg of steam at the temperature would have extreme effect on the tree, damaging it permanently. Possibly even blowing it to pieces

6 0

3 years ago