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
Harman [31]
3 years ago
14

Which of these correctly describes whether a girl holding a ball in the same position is doing work on the ball?

Physics
1 answer:
aksik [14]3 years ago
4 0

Answer:

The girl is doing work on the ball because the energy in her muscles changed, even though the ball is not displaced.

Explanation:

The complete question is...

Which of these correctly describes whether a girl holding a ball in the same position is doing work on the ball?

-The girl is doing work on the ball because the energy of the ball changed, even though it is not displaced.

-The girl is doing work on the ball because the energy in her muscles changed, even though the ball is not displaced.

-The girl is doing no work on the ball because the ball is not displaced.

-The girl is doing no work on the ball because she is exerting a net force on the ball.

Holding up a ball costs energy, which is used to counter the work that would have otherwise be done on the ball by gravity. Although no physical distance is moved, we should consider the fact that by holding the ball, the girls hand exerts physical force to hold the ball in place. Also, there is a potential gravitational work on the ball due to gravity, but the force exerted by the girls hand does an equivalent of this gravito-potential work in order to counter it and hold the ball in place. All these activities eventually lead to a change in energy in her hand muscle to show that energy is expended.

You might be interested in
The angle of reflection is the angle between the normal line and the___?
Aleks [24]

Answer:

Reflected line

Explanation:

The angle between the reflected ray and the normal ray is called angle of reflection.

4 0
3 years ago
Alice and Tom dive from an overhang into the lake below. Tom simply drops straight down from the edge, but Alice takes a running
tangare [24]

Answer:

Since both start with the same vertical velocity from the same position with the same acceleration they will reach the lake at the same time.

6 0
3 years ago
A negatively-charged particle is slowly moving as it enters a region that has a constant magnetic field. If the velocity of the
Anna71 [15]

Answer:

no deflection and net force is zero. Moving in same direction and with same speed

Explanation:

Charge = negative

the angle between the velocity vector and the magnetic field vector is 0°, so the force is given by

F = q v B Sin 0

F = 0

As the force is zero so the charge particle moves with the same velocity and in the same direction.

there is no deflection in the path of negatively charged particle.

7 0
3 years ago
If the graph represents speed, what is measured on the x and y axes? You need to specifically identify which axis is which.
Harrizon [31]
X axis - time
Y - distance
4 0
3 years ago
A battery with an internal resistance ofrand an emf of 10.00 V is connected to a loadresistorR=r. As the battery ages, the inter
yanalaym [24]

Answer:

The current is reduced to half of its original value.

Explanation:

  • Assuming we can apply Ohm's Law to the circuit, as the internal resistance and the load resistor are in series, we can find the current I₁ as follows:

        I_{1} = \frac{V}{R_{int} +r_{L} }

  • where Rint = r and RL = r
  • Replacing these values in I₁, we have:

       I_{1} = \frac{V}{R_{int} +r_{L} } = \frac{V}{2*r} (1)

  • When the battery ages, if the internal resistance triples, the new current can be found using Ohm's Law again:

       I_{2} = \frac{V}{R_{int} +r_{L} } = \frac{V}{(3*r) +r} = \frac{V}{4*r}  (2)

  • We can find the relationship between I₂, and I₁, dividing both sides, as follows:

        \frac{I_{2} }{I_{1} } = \frac{V}{4*r} *\frac{2*r}{V} = \frac{1}{2}

  • The current when the internal resistance triples, is half of the original value, when the internal resistance was r, equal to the resistance of the load.  
7 0
3 years ago
Other questions:
  • Which image represents a solenoid?
    5·2 answers
  • if you divide a force measured in newtons by a speed measured in in meters per second in what units will the answer be expressed
    11·1 answer
  • Which statement is true?
    12·1 answer
  • The outer planets _____.all have rings
    9·2 answers
  • Why has the atomic model changed over time
    10·1 answer
  • the resistance of a heater element is 1200 ohms and draws a circuit of 0.4 amperes calculate the voltage of the circuit​
    6·1 answer
  • How much resistance is required to limit the current from a 12 V battery to 3.6 mA?
    6·1 answer
  • Where is the acceleration zero?
    14·1 answer
  • How does the law of conservation of mass apply to this reaction: Mg + HCI + H2 MgClz?
    8·1 answer
  • A student pushes a block from rest across a frictionless surface while the block is in front of a motion detector for 3 seconds.
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!