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
Furkat [3]
3 years ago
7

Power lifter Paul lifts a 700.0kg barbell 2.00m in 0.400s. How much power did Paul develop?

Physics
2 answers:
Vsevolod [243]3 years ago
6 0

         Work = (force) x (distance.

The force required to lift the load is its weight.

         Weight = (mass) x (gravity)

so    Work = (mass) x (gravity) x (distance)

Now  Power = (work) / (time)

so     Power  =  (mass) x (gravity) x (distance) / (time)

                      =  (700kg) x (9.8 m/s²) x (2 m)  /  (0.4 sec)

                      =  ( 700 x 9.8 x 2) / (0.4)  (kg-m²/sec²) / (sec)

                      =        ( 34,300 )                  (joule)  /  (sec)

                      =                     34,300 watts .

This is one of those exercises where the math and the physics
are air-tight and bullet-proof but the answer is absurd.

34,300 watts is about 46 horsepower.  I don't care how many
Wheaties Power Lifter Paul had for breakfast today, he is NOT
snatching a barbell that weighs  1,543 pounds (0.77 ton !)
to the height of the top of his head in less than 1/2 second !
yawa3891 [41]3 years ago
3 0
34,335 W 
P= mgh/t 
P=700*2*9.81/.4

You might be interested in
Manufacturing Plant Power A manufacturing plant uses 2.36 kW of electric power provided by a 50.0 Hz ac generator with an rms vo
Pie

Answer:

(a) Z = 48.3 Ω

(b) cos ∅ = 0.455

(c) Irms = 10.35 A

(d) C = 74.02 μF

(e) Irms = 4.44 A

Explanation:

Power (P) = 2.36 kW

Frequency (f) = 50 Hz

RMS Voltage (Vrms) = 500 V

Resistance (R) = 22 Ω

Inductive Reactance (XL) = 43 Ω

(a) to calculate the total impedance, use the formula:

Z = √(R² + XL²)

   = √((22)² + (43)²)

   = √2333

Z = 48.3 Ω

(b) To calculate the plant's power factor, we will use the formula:

cos ∅ = R/Z

          = 22/48.3

cos ∅ = 0.455

(c) To calculate the RMS current used by the plant, divide the RMS voltage value by the impedance of the plant.

Irms = Vrms/Z

        = 500/48.3

Irms = 10.35 A

(d) For the power factor to become unity, the inductive reactance must be equal to the capacitive reactance i.e. Xc = XL

Xc = XL

1/(2πfC) = XL

1/(2πfXL) = C

C = 1/(2π*50*43)

   = 7.402 x 10⁻⁵

C = 74.02 μF

(e) P = Vrms*Irms*cos∅

    Irms = P/Vrms*cos∅

             = 2.22 x 10³/500*1

    Irms = 4.44 A

4 0
3 years ago
All of the fallowing are possible sources of error in a scientific investigation exept for
Whitepunk [10]

c adding research resources during an investigation

6 0
3 years ago
A plane lands on a runway with a speed of 115 m/s, moving east, and it slows to a stop in 13.0 s. What is the magnitude (in m/s2
marin [14]

Answer:

<em> The planes average acceleration in magnitude and direction = 8.846 m/s² moving east</em>

Explanation:

Acceleration: This can be defined as the rate of change of velocity. The S.I Unit of acceleration is m/s². Acceleration is a vector quantity because it can be represented both in magnitude and in direction.

Acceleration can be represented mathematically as

a = v/t.................................... Equation 1

Where a = acceleration, v = velocity, t= time.

<em>Given: v = 115 m/s, t = 13.0 s</em>

<em>Substituting these values into equation 1</em>

<em>a = 115/13</em>

<em>a = 8.846 m/s² moving east</em>

<em>Thus the planes average acceleration in magnitude and direction = 8.846 m/s² moving east</em>

4 0
2 years ago
The spans of time that make up the Earth's geologic timescale are generally defined by the different types of
Trava [24]
<span>division of Earth's history into time units based largely on the types of life-forms that lived only during certain periods.</span>
5 0
3 years ago
A vase of flowers is stationary on a table. which of the following statements best explains why the vase is stationary?
goldenfox [79]
D. The table pushes up on the vase with the same amount of force as gravity pulling it down.
7 0
3 years ago
Other questions:
  • If you lift two loads up one story, how much work do you do compared to lifting just one load up one story?
    14·1 answer
  • a ball rolls 6.0 meters as its speed changes from 15 meters per second to 10 meters per second. whaf is the average speed of the
    7·1 answer
  • What is the density of the object that has a mass 13.87g and a volume of 31.75cm3?​
    9·1 answer
  • Which of the following tests uses calipers to assess body composition? A. skinfold test B. sit-and-reach C. arm hang D. curl-up
    10·1 answer
  • A circus performer is putting together an act that involves lying on a bed of nails without getting hurt. The tip of each nail h
    9·1 answer
  • Suppose an earthquake occurs on an imaginary planet. Scientists on the other side of the planet detect primary waves but not sec
    11·1 answer
  • Mention five disadvantages of nonsustainable energy <br><br>​
    5·1 answer
  • A student lifts a box of books 2 meters with a force of 45 N. He then carries the box 10 meters to the living room. What is the
    12·1 answer
  • Leena is a 16-year-old girl. She complains of tiredness and loss of appetite. She is unable to concentrate on her studies and ap
    15·1 answer
  • What is the formula between torque applied force and the lever arm?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!