PLEASE HELP ASAP!!!!
You and a friend move a grand piano across the living room, exerting 25 newtons of force and performing 175 joules of work. It takes you 14 seconds. How far did you move the piano? How much power did you generate, in watts (joules/sec)?

Respuesta :

Answer:

The piano moved 7 meters.

The power generated was 12.5 Watts.

Explanation:

Work is defined as the force that is applied on a body to move it from one point to another.

When a net force is applied to the body or a system and this produces displacement, then that force is said to perform mechanical work.

In the International System of Units, work is measured in Joule. Joule is equivalent to Newton per meter.

The work is equal to the product of the force by the distance and by the cosine of the angle that exists between the direction of the force and the direction that travels the point or the object that moves:

Work = force*distance*cos (angle between the force and the displacement)

In this case, the angle between the force and the displacement is 0 degrees.

In this case, you know:

  • Work=175 Joule
  • Force=25 Newtons
  • Distance=?
  • Angle between the force and the displacement=0 degrees → cos (angle)=1

Replacing:

175 Joule=25 Newtons*distance*1

In this way, it is resolved to obtain:

[tex]distance=\frac{175 Joule}{25 Newtons*1} =\frac{175 Newtons*meters}{25 Newtons*1}[/tex]

distance= 7 meters

The piano moved 7 meters.

Power is defined as the speed with which a job is performed. That is, power is the amount of work done for a unit of time:

[tex]P=\frac{work}{time}[/tex]

Where P is the power developed by the force that performs the work and its unit of measure in the International System is the Watts (W), the unit of measure of work in the International System is Joule (J) and time during which the work is carried out, it has the unit of measure in the International System of seconds (s). So Watts is equivalent to [tex]\frac{Joule}{second} =\frac{J}{s}[/tex].

So in this case:

[tex]P=\frac{175 Joule}{14 seconds}[/tex]

P=12.5 [tex]\frac{J}{s}[/tex]=12.5 watts

The power generated was 12.5 Watts