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
NARA [144]
4 years ago
9

A cable that weighs 8 lb/ft is used to lift 900 lb of coal up a mine shaft 650 ft deep. Find the work done. Show how to approxim

ate the required work by a Riemann sum. (Let x be the distance in feet below the top of the shaft. Enter xi* as xi.)
Physics
1 answer:
tia_tia [17]4 years ago
6 0

Answer:

Total Work=2275000 ft-lb

Explanation:

According to Riemann sum approximate for work needed to lift the cable:

W= \lim_{n \to \infty} \sum_{i=1}^n8x_i\Delta x

Sine we have to add 650 terms because distance 650 ft, we will us the integration.

W=\int\limits^a_b {f(x)} \, dx \\W=\int\limits^{650}_0 {8x} \, dx \\W=[4x^2]_0^{650}\\W=4(650)^2-0^2\\W=4*422500 ft-lb\\W=1690000 ft-lb

Work done on lifting:

W_1=900*650\\W_1=585000 ft-lb

Total Work= W+W_1

Total Work=1690000+585000

Total Work=2275000 ft-lb

You might be interested in
When a force is acting at axis of rotation,why torque is zero?
Vikki [24]

Explanation:

see, torque=force × perpendicular distance

...that perpendicular distance is between axis of rotation and the point where force acts... so in above's case perpendicular distance is zero... so the torque is zero!

4 0
3 years ago
Provide a reason why houses are painted with dark colours in cold countries.​
fenix001 [56]

Answer:

which is necessary to keep the building warm. Light colors reflect the light hence they are wisely used in tropical ...

Here in the US, not all houses are painted dark colors. In years past, it was common for the ...

7 0
3 years ago
Read 2 more answers
Convert 30.0 degrees Celsius into Kelvin
frutty [35]

Answer:

303.15K

Explanation:

the formula for converting celsius into kelvin is adding 273.15 to the number

4 0
3 years ago
1. James drives 400 km in 5 hours to his grandmothers. What are the units for speed going to be?
Airida [17]

Answer:

See the answer below

Explanation:

1. Speed is calculated as the ratio of distance and time. Hence, Jame's speed can be calculated as:

       400/5 km/hr = 80 km/hr

The unit for the speed would be km/hr. This can also be converted to m/s:

80 km = 80,000 m

1 hr = 3,600 s

80 km/hr = 80,000/3600 m/s = 22.22 m/s

2. Since James drove 400 km in 5 hours, the distance he drove is 400 km.

3. The time it took for James to get there is 5 hours.

6 0
3 years ago
6. Draw conclusions: Newton’s first law states that an object in motion will travel at a constant velocity unless acted upon by
gavmur [86]
You can test if it’s true by holding a pencil in mid air over a table and the table is supposed to be the unbalanced forced that stopped the pencil from moving at the constant velocity it was going by.
5 0
3 years ago
Read 2 more answers
Other questions:
  • Which material absorbs some colors of light and reflects other colors?
    14·2 answers
  • What distinguishes mass from weight? A. Mass is a measure of the amount of matter in an object, while weight is a measure of the
    6·2 answers
  • Diffusion of water through a differentially permeable membrane is called
    6·2 answers
  • The heat capacity of object B is twice that of object A. Initially A is at 300 K and B at 450 K. They are placed in thermal cont
    13·1 answer
  • The transverse motion of a star can be determined by studying its spectrum. TRUE or FALSE
    14·1 answer
  • Hamid is going to heat sodium chloride and water in a beaker. How can he carry out his experiment as
    13·1 answer
  • B c<br>_ - _<br>a b<br>( a=3 b=-5 c=6)​
    12·1 answer
  • 50 POINTS!! BRAINLEST
    13·2 answers
  • Which goes faster? *<br> light in space<br> sound in air<br> sound in space<br> light in water
    5·1 answer
  • Which statement accurately describes the charge of the nucleus of an atom?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!