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
Luba_88 [7]
3 years ago
14

A 75.0-kg painter climbs a ladder that is 2.75 m long leaning against a vertical wall. The ladder makes a 30.0° angle with the w

all. (a) How much work does is done by gravity on the painter? (b) Does the answer to part (a) depend on whether the painter climbs at constant speed or accelerates up the ladder?
Physics
2 answers:
Schach [20]3 years ago
6 0
<h3><u>Answer;</u></h3>

a) 178.6125 Joules

b) Work done does not depend on constant speed or acceleration up the ladder

<h3><u>Explanation</u>;</h3>

Work done =Fd times the cosine of angle between;

where F is force d is distance m is the mass a is acceleration

.F=ma. In this case a=g=9.81 m/s^2 and cos 30=0.866

Therefore;  

W= 75 × 9.81 × 2.75 × .866  

   = 178.6125 Joules

b. The work done by the painter does not depend on whether the painter climbs at constant speed or accelerates up the ladder.

W=3376.945 Joules

Mazyrski [523]3 years ago
4 0

Answer:

Work is defined as the movement caused by a force. In the case of someone climbing something, the person is doing force against gravity, so the work needed to lift an object of mass M by a height H is equal to W = MgH where h is the gravity acceleration.

In this case, M = 75kg and we can obtain the height by the Pythagorean theorem, where the ladder is the hypotenuse of a triangle.

If we want to only know the displacement in the y-axis, then we need to compute the adjacent cathetus, this is:

H = 2.75m*cos(30°) = 2.38m

and we know that g= 9.8m/s^2

so we can compute the work and obtain:

W = 2.38m*9.8m/s^2*75kg = 1739,3J

b) work does not depend on the velocity, the fact that he is ascending means that there is a force applied on him that fights against the gravity. Non the less, if there was a force bigger applied to him in the y-direction (which may accelerate him, the previous calculation is thinking that the force done is equal to the gravitational force) the work can be bigger. The work calculated before is the minimal work needed to make him ascend the height H.

You might be interested in
Bacteria vary in size, but a diameter of 2.0 µm is not unusual. What are the volume (in cubic centimeters) and surface area (in
telo118 [61]

A = 4\pi r^2

A = 4\pi (2\mu m /2)^2 (10^{-6}m/1\mu m)^2 (1mm/10{-3})^2

A = 1.33*!0^{-5}MM^2

5 0
3 years ago
BRAINLIEST AND MAY DOUBLE POINTS!!!
raketka [301]

Given that:

 Energy of bulb  (Work ) = 30 J,

 Time (t) = 3 sec

The power consumption =  ?

 We know that, Power can be defined as rate of doing work

              Power (P) = Work(Energy supplied) ÷ time

                               = 30 ÷ 3

                              = 10 Watts

<em> The power consumption is 10 W.</em>


3 0
3 years ago
If I accidentally touch a stove and burn myself, which type of heat transfer is occurring?
allochka39001 [22]

Answer:

radiation is the correct answer

5 0
3 years ago
Help please ill give brainly and heart !!!!
Nikitich [7]

Answer:

The answer is A ) High pressure

I hope this helps you :)

please let me know if I am wrong

3 0
3 years ago
Read 2 more answers
Please select the word from the list that best fits the definition Used to compare two specific variables
Ann [662]

i would say line graph


7 0
3 years ago
Read 2 more answers
Other questions:
  • What is the wavelength of a monochromatic light beam, where the photon energy is 2.70 × 10^−19 J? (h = 6.63 ×10^−34 J⋅s, c = 3.0
    13·1 answer
  • Which compound is the strongest acid?
    5·2 answers
  • Which of the following its a substance: table salt, seawater, or sand
    15·1 answer
  • Humid air breaks down (its molecules become ionized) in an electric field of 4.99 x 10^6 N/C. In that field, what is the magnitu
    11·1 answer
  • A solenoid has 332 turns and a length of 14 cm. If a current of 0.88 A produces a magnetic flux density of 0.28 T in the core of
    5·1 answer
  • A circuit is built based on the circuit diagram shown.
    12·1 answer
  • A snail moves 40 cm in<br> 20 seconds. How fast<br> did it move?
    8·1 answer
  • 2. If I drop a watermelon from the top of one of the tower dorms at CSU, and it takes 3.34 seconds to hit the ground, calculate
    14·1 answer
  • A uniform rod is hung at one end and is partially submerged in water. If the density of the rod is 5/9 that of water, find the f
    14·1 answer
  • a sloution has a very high hydroxide ion concentration.based on this what would your predit about this sloution
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!