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
prohojiy [21]
2 years ago
7

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 12.0 m: (a) the initially stationary spelunker is accelerated to a speed of 2.90 m/s; (b) he is then lifted at the constant speed of 2.90 m/s; (c) finally he is decelerated to zero speed. How much work is done on the 77.0 kg rescue by the force lifting him during each stage
Physics
1 answer:
Leya [2.2K]2 years ago
5 0

Answer:

a) 323.4J

b) 0J

c) -323.4J

Explanation:

a) W=Fd

F=ma

solve for acc. using kinematics

v^2=vo^2+2a(x)

8.41=2a(12)

4.205=a(12)

0.35=a

F=(77)(0.35)

F=26.95N

W=26.95*12...... W=323.4J

b) No acceleration, thus no force, thus no work!

c) W=Fd

F=ma

find acc. using kinematics: v^2=vo^2+2a(x)

0=(2.9^2)+2a(12)

0=8.41+2a(12)

-8.41=2a(12)

-4.205=a(12)

-0.35=a

F=(77)(-0.35)

F=-26.95N

W=(-26.95)(12)

W=-323.4J

Yes, work can be negative!

You might be interested in
The revival of the atomic concept was catalyzed by what experimental observation?
IgorC [24]
It seems that you have missed the necessary options for us to answer this question so I had to look for it. Anyway, here is the answer. The revival of the atomic concept was catalyzed by the experimental observation which is Constant <span>composition in compounds. Hope this helps.</span>
5 0
3 years ago
(Q004) During World War II, the military imaged the seafloor by sending pulses of sound waves down through the water and measuri
valkas [14]

Answer:

Sonar

Explanation:

Sonar is a technique that involves the use of sounds in viewing substances in a water medium to aid movement or communication. It makes use of the advantage of sound waves traveling faster and farther in water when compared to other types of waves such as light waves.

During World War II, the military employed the use of SONAR in imaging the seafloor by sending pulses of sound waves down through the water and measuring the time it took for the sound to bounce off the seafloor and return to the receiver.

7 0
3 years ago
At what location in a circuit is the electrical potential energy the greatest
Eduardwww [97]

It's not the potential energy.  It's just the potential.

It's greatest at the positive terminal of the battery or power supply.


4 0
3 years ago
What is a simple machine that has two or more simple machines working together
zmey [24]

Compound machines have two or more simple machines

3 0
3 years ago
Uses of solar cells ?
Damm [24]

Solar cells are used to trap sunlight energy (light energy) and convert it to electric energy for domestic and other purposes.

7 0
3 years ago
Other questions:
  • An electron has an uncertainty in its position of 587 pm . part a what is the uncertainty in its velocity?
    8·1 answer
  • A person stands on a scale in an elevator. his apparent weight will be the greatest when the elevator:
    8·2 answers
  • vector A makes equal angles with x,y and z axis. value of its components (in terms of magnitude of vector A will be?
    6·2 answers
  • Help someone :(((((((((((((((
    8·2 answers
  • What kind of energy is used in baking?<br>A. Light<br>B. Sound<br>C. Heat<br>D. Mechanical​
    13·1 answer
  • A laser (electromagnetic wave) has the maximum electric field strength of 1.0x1011 V/m. What is the force the laser applies on a
    12·1 answer
  • How many significant figures are there in the number<br> 2.3409500?
    13·1 answer
  • Explain the difference between velocity and acceleration.​
    9·2 answers
  • In chemistry a 'system' is ___________________.
    5·1 answer
  • What is Si system? Why has Si system been developed? Give reason.​
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!