1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Alexeev081 [22]
4 years ago
13

A cave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. The lift i

s performed in three stages, each requiring a vertical distance of 10.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.70 m/s; (b) he is then lifted at the constant speed of 4.70 m/s; (c) finally he is decelerated to zero speed. How much work is done on the 56.0 kg rescue by the force lifting him during each stage
Physics
1 answer:
sveticcg [70]4 years ago
3 0

Answer:

(a) the initially stationary spelunker is accelerated to a speed of 4.70 m/s - 6106 J

(b) he is then lifted at the constant speed of 4.70 m/s - 5488 J

(c) finally he is decelerated to zero speed. How much work is done on the 56.0 kg rescue by the force lifting him during each stage - 4869 J

Explanation:

knowing

d = 10 m

m = 56 kg

The work done by the applied force to pull the spelunker is given by

Wa + Wg = Kf - Ki

Wg = -mgd

First

Wa = mgd + 0.5 mv^{2}_{f} - 0.5 mv^{2}_{i}

Wa = (56*9.8*10) + (0.5*56*4.7^{2})

Wa = 6106 J

Second

Kf = Ki

Wa = mgd + 0.5 mv^{2}_{f} - 0.5 mv^{2}_{i}

Wa = 56*9.8*10

Wa = 5488 J

Third

Kf = 0

Wa = mgd + 0.5 mv^{2}_{f} - 0.5 mv^{2}_{i}

Wa = (56*9.8*10) - (0.5*56*4.7^{2})

Wa = 4869 J

You might be interested in
If a 60 W light bulb and a 75 W light bulb operate from 150 V source, which bulb has a greater current in it?
Monica [59]

Answer:

Since it us the resistance that causes the power output, it might be intuitive to think that more resistance produces more power but as P=I^2 * R one actually needs high current and low resistqnce. That means 75 W has lower resistance and higher current.

Now you may think that making the resistance very low, one gets the most power. Not so, as the circuit has wires, power source etc. All the have their resistance. In theory one gets the maximum power over a resistor when the resistor is half of the total resistance of the circuit. This in practice would be inefficient as one would lose half of the total power elsewhere. In practice circuits have fuses that limit the current and one gets the maximum power at the current the fuse is rated to. So if there is 20 A fuse, the maximum power is 2400 W and the corresponding resistance 6 ohm.

8 0
3 years ago
The formation of atp as a result of the activity of the electron transport system is termed substrate-level phosphorylation is c
Zigmanuir [339]

Answer:

Oxidative phosphorylation

Explanation:

This takes place mostly in the organelle called the mitochondrion.

Oxidation of nutrients in cells by enzymes results in the release of the chemical energy present in the molecular energy.

The NADH and succinate products of the citric acid cycle are also oxidized. All this series of reactions takes place in the Electron transport system.The energy from the oxidation is used to produce adenosine triphosphate (ATP) hence the name oxidative phosphorylation.

4 0
3 years ago
a wave having a wavelength of 4.7 meters and an amplitude of 2.5 meters travels a distance of 28 meters in 7 seconds. determine
Aleksandr [31]

Answer:

<h2>T(Period) = 1.33s</h2><h2>f(Frequency) = 0.75Hz (cycles/second)</h2>

Explanation:

<h2>Given:</h2><h2 /><h2>λ = 4.0m</h2><h2>Amplitude = 25m</h2><h2>d = 24m</h2><h2>s = 8.0s</h2><h2 /><h2>Required:</h2><h2>f = ?</h2><h2>T = ?</h2><h2 /><h2>Analysis:</h2><h2>v = λf</h2><h2>f =N/t</h2><h2>T = 1/f</h2><h2 /><h2>v = d/t</h2><h2 /><h2>Solve:</h2><h2>v = d/t = 24/8.0 → v = 3.0m/s</h2><h2>v =λf → f = v/λ = 3.0/4.0 → f = 0.75Hz</h2><h2>T = 1/f = 1/0.75 → T = 1.33s</h2><h2 /><h2>Hopes this helps. Mark as brainlest plz!</h2>
4 0
3 years ago
Indicate whether each of the following statements is true or false. In a coal-fired power plant, chemical energy is first conver
denis23 [38]

Answer:

1. In a coal-fired power plant, chemical energy is first converted to thermal energy. TRUE.

The chemical energy in the coal is converted to thermal energy when the coal is burnt to produce steam.

2. In a coal-fired power plant, approximately 2/5 of original energy in the coal is lost to heat. FALSE.

Approximately 3/5 of the original energy is lost not 2/5 so this statement is false.

3. The molecules in cold air move faster than in hot air. FALSE.

Molecules with more heat move faster than molecules with less. Molecules in cold air therefore, will move slower than molecules in hot air.

6 0
3 years ago
1. A block with a mass of 5.0 kg is pushed on a frictionless surface by applying a horizontal force of 80.0 N. The block starts
Snezhnost [94]

Answer:

397 j

Explanation:

Because 5.0kg yuh

3 0
2 years ago
Other questions:
  • In a certain process, the energy change of the system is 250 \rm kJ. The process involves 480 \rm kJ of work done by the system.
    9·1 answer
  • A motorist drives south at 20.0 m/s for 3.00 min, then turns west and travels at 25.0 m/s for 2.00 min, and finally travels nort
    10·1 answer
  • What must occur for work to be done on an object?
    14·2 answers
  • Which of the following is NOT an example of an assembly process? a) Handling b) Fitting c) Automated robot d) Orientation
    6·1 answer
  • The bodies of many cars are designed to compress or crumple during an accident. Why are cars built with a crumple zone?
    7·1 answer
  • Express the answer to 6.51 x 107<br> divided by7.61 x 10<br> in scientific notation
    14·1 answer
  • Why do nations should establish a set of rules and principles for responsible lunar/moon explortions? ASAP pleaseeee :(
    10·1 answer
  • An insect 3.75 mm tall is placed 22.5 cm to the left of a thin planoconvex lens. The left surface of this lens is flat, the righ
    9·1 answer
  • When light enters water, it bends. what does the amount of bending depend on?
    6·1 answer
  • Fill in the blank with the correct response.
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!