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madreJ [45]
3 years ago
14

The suspension cable of a 1,000 kg elevator snaps, sending the elevator moving downward through its shaft. The emergency brakes

of the elevator stop the elevator shortly before it reaches the bottom of the shaft. If the elevator fell a distance of 100 m starting from rest, the heat that the brakes must dissipate to bring the elevator safely to rest is (A) 100 J (B) 1,000 J (C) 10,000 J (D) 100,000 J (E) 1,000,000 J
Physics
1 answer:
tester [92]3 years ago
4 0

Answer:

option (E) 1,000,000 J

Explanation:

Given:

Mass of the suspension cable, m = 1,000 kg

Distance, h = 100 m

Now,

from the work energy theorem

Work done by the gravity = Work done by brake

or

mgh = Work done by brake

where, g is the acceleration due to the gravity = 10 m/s²

or

Work done by brake  = 1000 × 10 × 100

or

Work done by brake = 1,000,000 J

this work done is the release of heat in the brakes

Hence, the correct answer is option (E) 1,000,000 J

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2 H2O2-> 2H20+02
Luden [163]

Answer:

This reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen. Add 2 molecules of hydrogen peroxide and 2 molecules of water. Since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

3]Explanation: This reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen. Add 2 molecules of hydrogen peroxide and 2 molecules of water. Since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

4]Two moles of hydrogen peroxide H2O2 decomposes to produce two moles of water H2O and one mole of oxygen gas O2(g) , which then bubbles off

6 0
2 years ago
Football player 1 has a mass of 80 kg and a velocity of 2 m/s east while player 2 has a mass of 70 kg and a velocity of 3 m/s we
sukhopar [10]

The total momentum of the system is equal to 50 Kgm/s.

<u>Given the following data:</u>

  • Mass 1 = 80 kg
  • Velocity 1 = 2 m/s east.
  • Mass 2 = 70 kg
  • Velocity 2 = 3 m/s west.

To determine the total momentum of the system:

Mathematically, momentum is given by the formula;

Momentum = mass \times velocity

<u>For Football player 1:</u>

Momentum = 80 \times 2

Momentum 1 = 160 Kgm/s.

<u>For Football player 2:</u>

Momentum = 70 \times 3

Momentum 1 = 210 Kgm/s.

Now, we can calculate the total momentum of the system:

Total\;momentum = momentum \;2 - momentum \;1\\\\Total\;momentum = 210-160

Total momentum = 50 Kgm/s.

<u>Note:</u> We subtracted because the football players were moving in opposite directions.

Read more: brainly.com/question/15517471

6 0
2 years ago
An island reports that in the year 2000 there were 240 babies born. That same year, 100 individuals died.
lyudmila [28]

Answer:

+ 140

Explanation:

You can show the natural growth rate by subtracting the death rate from the birth rate during one year and converting this into a percentage.

Here it would be:

240 - 100 = + 140

// if you want to convert it to percentage, you need to know the size of the population

it would be

140 / (population size) * 100 %

4 0
3 years ago
Charge g is distributed in a spherically symmetric ball of radius a. (a) Evaluate the average volume charge density p. (b) Now a
nasty-shy [4]

Answer:

Explanation:

The volume of a sphere is:

V = 4/3 * π * a^3

The volume charge density would then be:

p = Q/V

p = 3*Q/(4 * π * a^3)

If the charge density depends on the radius:

p = f(r) = k * r

I integrate the charge density in spherical coordinates. The charge density integrated in the whole volume is equal to total charge.

Q = \int\limits^{2*\pi}_0\int\limits^\pi_0  \int\limits^r_0 {k * r} \, dr * r*d\theta* r*d\phi

Q = k *\int\limits^{2*\pi}_0\int\limits^\pi_0  \int\limits^r_0 {r^3} \, dr * d\theta* d\phi

Q = k *\int\limits^{2*\pi}_0\int\limits^\pi_0 {\frac{r^4}{4}} \, d\theta* d\phi

Q = k *\int\limits^{2*\pi}_0 {\frac{\pi r^4}{4}} \,  d\phi

Q = \frac{\pi^2 r^4}{2}}

Since p = k*r

Q = p*π^2*r^3 / 2

Then:

p(r) = 2*Q / (π^2*r^3)

3 0
2 years ago
Which type of radiation can reach the furthest?<br> A. Beta<br><br> B. Gamma<br><br> C. Alpha
Mashutka [201]

Answer:

C. Alpha

Explanation:

Gamma radiation, unlike alpha or beta, does not consist of any particles, instead consisting of a photon of energy being emitted from an unstable nucleus. Having no mass or charge, gamma radiation can travel much farther through air than alpha or beta, losing (on average) half its energy for every 500 feet.

7 0
3 years ago
Read 2 more answers
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