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
OverLord2011 [107]
3 years ago
6

A force acting on an object does no work if

Physics
2 answers:
jok3333 [9.3K]3 years ago
8 0
If the force is not in the direction of the object’s motion then a <span> force acting on an object does no work
work is done if force is applied on a body and body covers some distance in the direction of the force
W=FS
hope it helps</span>
KIM [24]3 years ago
3 0

Answer: the force is not in the direction of the object’s motion.

Explanation:

Work = Force. Displacement

⇒ W = F. s = F s cos θ

Thus, work is said to be done when a force displaces an object from its position in the direction of the force.

If the force is less the frictional force, the object would not move. An object accelerates when a force is applied. Sometimes, the direction of force and direction of motion is not same. In that case, no work is said to be done.

For example, when porter lifts the weight on head and moves forward. The weight is perpendicular to the direction of motion. cos 90° = 0 ⇒ W = 0

You might be interested in
What medical technique uses sound wave pulses and their reflections to map structures and organs inside the body?
garri49 [273]

The correct answer is “C” ultrasound. Hope this helps!

7 0
3 years ago
Read 2 more answers
Scientists hypothesize that there are no dinosaurs alive today because
Wittaler [7]
Its c after the meteorite hit earth it created a different environment worldwide that animals weren't able to adapt to due to its harsh conditions 
8 0
3 years ago
Read 2 more answers
projectile motion of a particle of mass M with charge Q is projected with an initial speed V in a driection opposite to a unifor
SIZIF [17.4K]

Answer:

Range, R = MV²/2QE

Explanation:

The question deals with the projectile motion of a particle mass M with charge Q, having an initial speed V in a direction opposite to that of a uniform electric field.

Since we are dealing with projectile motion in an electric field, the unknown variable here, would be the range, R of the projectile. We note that the electric field opposes the motion of the particle thereby reducing its kinetic energy. The particle stops when it loses  all its kinetic energy due to the work done on it in opposing its motion by the electric field. From work-kinetic energy principles, work done on charge by electric field = loss in kinetic energy of mass.

So, [tex]QER = MV²/2{/tex} where R is the distance (range) the mass moves before it stops

Therefore {tex}R = MV²/2QE{/tex}

5 0
3 years ago
Convection is a process of heat transfer. In the earth, convection occurs because of heat and pressure from the core.
Dahasolnce [82]

Answer:

I BELIEVE THE ANSWER A I REMEMBER THAT QUESTION WHEN I DID IT SO THATS THE BEST ONE OUT OF THE 3  

Explanation:

6 0
3 years ago
Read 2 more answers
A rotating flywheel has moment of inertia 18.0 kg⋅m^2 for an axis along the axle about which the wheel is rotating. Initially th
timama [110]

Answer:

The rotational kinetic energy takes 0.430 seconds to become half its initial value.

Explanation:

By the Principle of Energy Conservation and the Work-Energy Theorem we know that flywheel slow down due to the action of non-conservative forces (i.e. friction), the energy losses are equal to the change in the rotational kinetic energy. That is:

\Delta E = K_{1}-K_{2} (1)

Where:

\Delta E - Energy losses, measured in joules.

K_{1}, K_{2} - Initial and final rotational kinetic energies, measured in joules.

By definition of rotational kinetic energy, we expand the equation above:

\Delta E = \frac{1}{2}\cdot I\cdot (\omega_{1}^{2}-\omega_{2}^{2}) (2)

Where:

I - Moment of inertia of the flywheel, measured in kilograms per square meter.

\omega_{1}, \omega_{2} - Initial and final angular speed, measured in radians per second.

If we know that K_{1} = 30\,J, K_{2} = 15\,J and I = 18\,kg\cdot m^{2}, then the initial angular speed is:

K_{1} = \frac{1}{2}\cdot I \cdot \omega_{1}^{2} (3)

\omega_{1}=\sqrt{\frac{2\cdot K_{1}}{I} }

\omega_{1} = \sqrt{\frac{2\cdot (30\,J)}{18\,kg\cdot m^{2}} }

\omega_{1} \approx 1.825\,\frac{rad}{s}

\omega_{1}\approx 0.291\,\frac{rev}{s}

K_{2} = \frac{1}{2}\cdot I \cdot \omega_{2}^{2} (4)

\omega_{2}=\sqrt{\frac{2\cdot K_{2}}{I} }

\omega_{2} = \sqrt{\frac{2\cdot (15\,J)}{18\,kg\cdot m^{2}} }

\omega_{2} \approx 1.291\,\frac{rad}{s}

\omega_{2} \approx 0.205\,\frac{rev}{s}

Under the assumption that flywheel is decelerating uniformly, we get that the time taken for the flywheel to slowdown is:

t = \frac{\omega_{2}-\omega_{1}}{\alpha} (5)

If we know that \omega_{1}\approx 0.291\,\frac{rev}{s}, \omega_{2} \approx 0.205\,\frac{rev}{s} and \alpha = -0.200\,\frac{rev}{s^{2}}, then the time needed is:

t = \frac{0.205\,\frac{rev}{s}-0.291\,\frac{rev}{s}}{-0.200\,\frac{rev}{s^{2}} }

t = 0.43\,s

The rotational kinetic energy takes 0.430 seconds to become half its initial value.

6 0
3 years ago
Other questions:
  • What's the difference between here and there?
    7·2 answers
  • In science, a hypothesis must be true. Please select the best answer from the choices provided True or False
    11·2 answers
  • What are not some emotional reactions to stress?
    7·1 answer
  • What is the pathway of sound through fluids starting at the oval window through to dissipation of the sound waves at the round w
    7·1 answer
  • Bob, Jill, Kim, and Steve measure an object's length, density, mass, and brightness, respectively. Which student must derive a u
    12·1 answer
  • a motorcar is moving with a velocity of 108 km / h and it takes 4s to stop after the brakes are applied calculate the force exer
    5·2 answers
  • How many bottles of water should you drink in a week
    15·2 answers
  • Which transition metals have more in common than other
    12·2 answers
  • What is types of motion ​
    13·2 answers
  • A wind turbine takes in energy from wind with the goal of converting it into electrical energy. Much of the wind energy is also
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!