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
blagie [28]
3 years ago
11

A bodybuilder loads a bar with 550 Newtons (~125 pounds) of weight and pushes the bar over her head 10 times. Each time she lift

s the weight 0.5 meters. How much work did she do?
Physics
2 answers:
tangare [24]3 years ago
5 0
<span>  (550 N) X (0.5 m) = 275 joules</span>
mafiozo [28]3 years ago
3 0

Work = (force) x (distance)

Each time she lifts the weight, she does

          (550 N) x (0.5 m) = 275 joules of work against gravity.

Each time she lets the bar down gently, gravity does

          (550 N) x (0.5 m) = 275 joules of work against her muscles. 

If the human physical muscular system were 100% efficient, and capable
of absorbing work as well as spending it, then the bodybuilder would do
exactly zero work in the process of 1-up followed by 1-down.


You might be interested in
A sky diver, with parachute unopened, falls 625 m in 15.0 s. Then she opens her parachute and falls another 362 m in 139 s. What
Jobisdone [24]

Answer:

v_{avg} = 6.41 m/s

Explanation:

Average velocity is defined as the ratio of total displacement of the motion and total time taken in that motion

here we know that initially the sky diver drops without opening parachute by total displacement 625 m

then she open her parachute and drop another 362 m

so first it took time t = 15 s to drop without open parachute

then it took t = 139 s to drop next displacement

so here total displacement is given as

d = 625 m + 362 m

total time is given as

t = 15 s + 139 s

so average velocity is given as

v_{avg} = \frac{625 + 362}{15 + 139}

v_{avg} = 6.41 m/s

4 0
3 years ago
A 87.0 kg astronaut is working on the engines of a spaceship that is drifting through space with a constant velocity. The astron
Ket [755]

Answer:

259.62521 seconds

Explanation:

m_1 = Mass of astronaut = 87 kg

m_2 = Mass of wrench = 0.57 kg

v_1 = Velocity of astronaut

v_2 = Velocity of wrench = 22.4 m/s

Here, the linear momentum is conserved

m_1v_1=m_2v_2\\\Rightarrow v_1=\frac{m_2v_2}{m_1}\\\Rightarrow v_1=\frac{0.57\times 22.4}{87}\\\Rightarrow v_1=0.14675\ m/s

Time = Distance / Speed

Time=\frac{38.1}{0.14675}=259.62521\ s

The time taken to reach the ship is 259.62521 seconds

4 0
3 years ago
Why is history open to ongoing and changing interpretations?
saveliy_v [14]
History is open to ongoing and changing interpretations because changing <span>values limit interpretation. 

So your answer is A.</span>
7 0
3 years ago
Read 2 more answers
A parallel-plate capacitor is charged by connecting it to a battery. If the battery is disconnected and then the separation betw
TEA [102]

Answer:

The charge stored in the capacitor will stay the same. However, the electric potential across the two plates will increase. (Assuming that the permittivity of the space between the two plates stays the same.)

Explanation:

The two plates of this capacitor are no longer connected to each other. As a result, there's no way for the charge on one plate to move to the other. Q, the amount of charge stored in this capacitor, will stay the same.

The formula \displaystyle Q = C\, V relates the electric potential across a capacitor to:

  • Q, the charge stored in the capacitor, and
  • C, the capacitance of this capacitor.

While Q stays the same, moving the two plates apart could affect the potential V by changing the capacitance C of this capacitor. The formula for the capacitance of a parallel-plate capacitor is:

\displaystyle C = \frac{\epsilon\, A}{d},

where

  • \epsilon is the permittivity of the material between the two plates.
  • A is the area of each of the two plates.
  • d is the distance between the two plates.

Assume that the two plates are separated with vacuum. Moving the two plates apart will not affect the value of \epsilon. Neither will that change the area of the two plates.

However, as d (the distance between the two plates) increases, the value of \displaystyle C = \frac{\epsilon\, A}{d} will become smaller. In other words, moving the two plates of a parallel-plate capacitor apart would reduce its capacitance.

On the other hand, the formula \displaystyle Q = C\, V can be rewritten as:

V = \displaystyle \frac{Q}{C}.

The value of Q (charge stored in this capacitor) stays the same. As the value of C becomes smaller, the value of the fraction will become larger. Hence, the electric potential across this capacitor will become larger as the two plates are moved away from one another.  

3 0
3 years ago
A duck flies 60 m in 6 seconds what is the ducks speed? Show your work plz
Lana71 [14]

Answer:

Wouldn’t his or hers speed be 10m?

Explanation:

because 60 divided by 6 = 10

so 10m per second?

7 0
3 years ago
Other questions:
  • PLEASSE HELP WILL MARK BRAINLIEST!!!!!!!!!!
    15·1 answer
  • (a) The stick is supported by a sharp point at the middle. On the left side, a weight of 100 g is suspended at 40 cm from the mi
    12·1 answer
  • Answer each of the following questions:
    13·1 answer
  • An electric pump rated 1.5 KW lifts 200kg of water through a vertical height of 6m in 10 secs: way is the efficiency of the pump
    13·1 answer
  • I NEED THIS QUICKLY
    14·1 answer
  • WILL MARK BRAINLIEST IF THE ANSWER IS CORRECT Vinegar and baking soda react to form sodium acetate (NaC2H3O2), water (H2O), and
    11·1 answer
  • How much force is required to accelerate a 5 kg mass at 20 m/s^2
    15·1 answer
  • What sport does not require a high level of fitness
    10·1 answer
  • 5. How does privatization contribute to productivity?
    6·1 answer
  • After oxygen has been administered, the next priority intervention the nurse would initiate for a patient with a pulmonary embol
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!