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
liq [111]
3 years ago
7

A crane used 250,000 Joules of work to move a beam to the top of a building in 20 seconds. How much power did the crane use?

Physics
1 answer:
maria [59]3 years ago
7 0

Answer:

12500W

Explanation:

Given parameters:

Work done  = 250000J

Time taken  = 20s

Unknown:

Power of the crane = ?

Solution:

Power is the defined as the rate at which work is being done;

  Mathematically;

        Power = \frac{work done}{time }

 insert the parameters and solve;

      Power  = \frac{250000}{20}   = 12500W

You might be interested in
A "590-W" electric heater is designed to operate from 120-V lines.
lukranit [14]

Answer:

a) 24.4 Ω

b) 4.92 A

c) 495.9 W

d)

c. It will be larger. The resistance will be smaller so the current drawn will increase, increasing the power.

Explanation:

b)

The formula for power is:

P = IV

where,

P = Power of heater = 590 W

V = Voltage it takes = 120 V

I = Current Drawn = ?

Therefore,

590 W = (I)(120 V)

I = 590 W/120 V

<u>I = 4.92 A</u>

<u></u>

a)

From Ohm's Law:

V = IR

R = V/I

Therefore,

R = 120 V/4.92 A

<u>R = 24.4 Ω</u>

<u></u>

c)

For constant resistance and 110 V the power becomes:

P = V²/R

Therefore,

P = (110 V)²/24.4 Ω

<u>P = 495.9 W</u>

<u></u>

d)

If the resistance decreases, it will increase the current according to Ohm's Law. As a result of increase in current the power shall increase according to formula (P = VI). Therefore, correct option is:

<u>c. It will be larger. The resistance will be smaller so the current drawn will increase, increasing the power.</u>

7 0
2 years ago
Sleep is a component of which part of the health triangle
katrin [286]

Answer:

physical health

Explanation:

Physical health has many components including: exercise, nutrition, sleep, alcohol & drugs, and weight management.

5 0
3 years ago
What is the name and symbol of the element in the second row and fourteenth column of the periodic table? Hint: Review your peri
Papessa [141]
The answer is Carbon. Beyond being the only element listed here that is located in the second row, it is also in the fourteenth column of the table if you count from left to right. Hope this helps!
4 0
3 years ago
If a pebble is being transported in a stream by rolling, how does the velocity of it compare to the velocity of the stream?
AleksandrR [38]
Streams carry sediment, like pebbles, in their flows. The pebbles can be in a variety of locations in the flow, depending on it's size, the balance between the upwards velocity on the pebble (drag and lift forces), and it's settling velocity.
3 0
3 years ago
A man on the moon throws a ball vertically upwards and it is noticed that the ball travels 3.0m less in the fifth second of its
sdas [7]
<h2>Acceleration due to gravity in moon is 1.5 m/s²</h2>

Explanation:

We have equation of motion s = ut + 0.5 at²

Here the ball travels 3 m less distance in fifth second compared to third second.

That is

           s₃ = s₅ + 3

Now we have

Distance traveled in third second, s₃ = u x 3 - 0.5 x g x 3² -  u x 2 - 0.5 x g x 2²

           s₃ = u - 2.5 g

Also

Distance traveled in fifth second, s₅ = u x 5 - 0.5 x g x 5² -  u x 4 - 0.5 x g x 4²

           s₅ = u - 4.5 g    

That is

           u - 2.5 g = u - 4.5 g + 3

             2 g = 3

                g = 1.5 m/s²

Acceleration due to gravity in moon = 1.5 m/s²

8 0
2 years ago
Other questions:
  • I need help with this please
    6·1 answer
  • What is the average intensity of the wave after it passes through polarizer b?
    15·1 answer
  • Estimate the number of gallons of gasoline consumed by the total of all automobile drivers in the U.S., per year. Suppose that t
    8·2 answers
  • Si se deja caer una piedra desde un helicóptero en reposo, entonces al cabo de 20 s cual será la rapidez y la distancia recorrid
    15·1 answer
  • Four charges of magnitude +q are placed at the corners of a square whose sides have a length d. What is the magnitude of the tot
    12·1 answer
  • What is an isotope?
    6·1 answer
  • A scuba diver measures an increase in pressure of around 10^5 Pa upon descending by 10 m, what is the change in force per square
    6·1 answer
  • A train having speed of 85 km/h takes 5 hours to travel from Kerala to Karnataka. Calculate the distance between Kerala and Karn
    9·1 answer
  • Help!! Please!!<br><br> 15 points<br> 15 points
    13·2 answers
  • (fill in the blank) , itself a silver shape beneath the steadfast constellations, simon's dead body moved out toward the open se
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!