A 139 kg physics professor has fallen into the Grand Canyon. Luckily, he managed to grab a branch and is now hanging 89 m below the rim. A student (majoring in linguistics and physics) decides to perform a rescue/experiment using a nearby horse. After lowering a rope to her fallen hero and attaching the other end to the horse, the student measures how long it takes for the horse to pull the fallen physicist to the rim of the Grand Canyon. The acceleration of gravity is 9.8 m/s 2 . If the horse’s output power is truly 1 horsepower (746 W), and no energy is lost to friction, how long should the process take? Answer in units of s.

Answers

Answer 1

Answer:
In order to lift the fat (306 lb) physics professor 89 meters up to
the rim, he'll need more potential energy, equal to

(mass) x (gravity) x (height) = (139 x 9.8 x 89) = 121,236 joules .

If the faithful horse delivers 1 constant horsepower = 746 watts,
AND if the cute-as-a-button student has instantly figured out a
way to keep the rope sliding around the edge without any friction,
then the soonest Prof. Tubby can arrive at the rim is

(121,236 joules) / (746 joules/sec) = 162.5 seconds .

Nowhere in this tense drama has the student needed her linguistics
skill yet, but I'll bet it comes in handy as she attempts gamely to
comprehend all of the various pleadings, prayers, and expletives
uttered by her heavy hero from the time he falls over the rim until
he's again lifted to it.

Related Questions

In which of the following situations would the least work have been done?A. A 100-N force lifts an object 3 m.B. A 250-N force moves an object 1 m.C. A 25-N force moves an object 8 m.D. A 600-N force is applied to an object and moves it 0 m.
Accelaration is a derived quantity .Give reason
If you throw a 0.25-kg ball with a force of 20N what's the acceleration of the ball
A welding torch produces a flame by burning acetylene fuel in the presence of oxygen. This flame is used to melt a metal. Which energy transformation represents this process?
There are some cases where distance time graph of a particle is vertical . So could you please tell me when it is possible????

Ski lift carry people along 150 m cable up the side of a mountain. Riders are lifted a total of 75 m in elevation. What is the ideal mechanical advantage of the ski lift?

Answers

Ideal Mechanical Advantage (IMA) can be found by using the formula:

IMA = ID/OD

ID = Input Distance

OD = Output Distance

In the question, we are given:

ID = 150

OD = 75

Now, solve the expression with what we have.

IMA = 150/75

IMA = 2

Therefore, the IMA is 2.

Best of Luck!

What does it mean if an experiment is replicable? Why is it important that experiments be replicated?

Answers

If an experiment is replicable it means that the conduction of the experiment can be done multiple times to obtain data and or results. It is important that experiments be replicated because to basically avoid error in obtaining data. And to make sure a particular set of results aren't because of chance or error in measurement or analysis.

In a 4*100m relay race,tota track length is 200m and time taken by one particular group is 50.2sec. ehat is the average speed and average velocity of that group?plzzzz help mee

Answers

This is tricky, and the question could probably be written more clearly.

A " 4 x 100 m " race means that four runners each run 100 meters, for
a total of 400 meters ... very close to a quarter mile.

On a 200-meter track, each runner does halfway around the track, and
the whole team of four runners does twice around the track.

This team did the whole thing in 50.2 seconds. The average time for each runner
was 50.2/4 = 12.55 seconds.

Velocity is a speed and a direction. We have the speed, leaving only the puzzle of
what to do about the 'average' direction.

Here's a sneaky but easy way to dispense with the whole issue:
Define the average velocity (vector) as (total displacement vector)/(total time).

Since the fourth runner finished in exactly the same spot as the first runner
began, the total displacement is zero, and therefore so is the average velocity.

(Select all that apply)What are the major problems associated with the production of nuclear energy? a. air pollution
b. depletes natural resources
c. hazardous wastes
d. potential reactor accident
e. water pollution

Answers

Answer: a. air pollution

c. hazardous wastes

d. potential reactor accident

e. water pollution

A nuclear energy is produced in a thermal power plant. A nuclear energy is produced in a nuclear reactor. In nuclear reactor nuclear fission reactions takes place in which an atoms absorbs energy from radiations and undergo fission and produces energy in the form of high intensity radiations along with heat. Although the fission reactions takes place in a nuclear reactor in a controlled way so that the radiation may not leak out from the reactor. The accidentally leak out radiations or explosion or bursting of the reactor due to uncontrolled thermal energy production can result in air pollution as the leak out air will cause bursting effects which will contaminate the air.

The nuclear waste are radioactive and are non-biodegradable these wastes are disposed off deep in geospheres and in water. They have potential to contaminate both land and water. Radioactive wastes can cause mutations in the genome of the organisms exposed to these wastes which generate deadly diseases and disorders. Therefore, these wastes are hazardous.

Answer: Hazardous wastes and potential reactor accident.

Could anyone explain how to size of an image works in a pinhole camera?

Answers

An image of an object can be used to determine the object's size or the distance to the object. The ability of the human eye's lens to focus an image on the retina is aided by the eye's pupil (the eye's aperture), which acts as a pinhole camera.

What is the current when a 71-W lamp is connected to 120 V?

Answers

Power = (voltage) · (current)

71 W = (120 V) · (current)

Divide each side by (120 V) :

Current = (71 W) / (120 V) = 0.59167 Amperes

What I want to know is: Where can I buy a 71-W light bulb ?

Other Questions

If you drop a stone into a hole drilled all the way to the other side of Earth, the stone will _____. A. speed up until it gets to the center of Earth B. slow down until it reaches the center of Earth C. speed up until it reaches the other side of Earth D. stop at the center of Earth

In a series circuit, if one of the bulbs blew out, the other bulb woulda. not be able to light up. b. stay lit but be very dim. c. stay lit in the same way. d. stay lit and be twice as bright as when both bulbs were lit.

How much current will a 240 V heater with 20 ohms of resistance draw?

A train travels with a constant speed of 36 miles per hour. How far can it travel in 1 hour 30 minutes?