Calculating Power of a Force: 4.7 N Force on 7.1 kg Object - Equation Help

[lilmul123]

Homework Statement

A single force F of 4.7 N acts in the x direction on a 7.1 kg object.

(a) If the object starts from rest at x = 0 at time t = 0, write an expression for the power delivered by this force as a function of time. (Use F for the force F, m for mass m of the object, and t for time t as necessary.)


Quite simply, I don't even know where to begin. Can anyone give me a nudge? I have a list of equations involving force, work, and power, but I don't know which of those to use...

 

[kuruman]

Since you are asked to find power, what equation(s) do you know that involve force and power? Start from there.

 

[tomcue]

I would start by identifying the known values and the unknown value in this scenario. We know that the force acting on the object is 4.7 N and the mass of the object is 7.1 kg. The unknown value is the power delivered by this force, which we can calculate using the equation P = F*v, where P is power, F is force, and v is velocity.

In this case, we can assume that the object is moving in a straight line, so the velocity can be calculated using the equation v = x/t, where x is the distance traveled and t is the time.

Since the object starts from rest, we can assume that it is initially at x = 0 and has a velocity of 0. Therefore, the expression for power as a function of time would be P = F*(x/t).

We can also rewrite this expression as P = F*(x/Δt), where Δt is the change in time. In this case, since we are starting from rest, we can assume that Δt is the same as t.

Therefore, the final expression for power as a function of time would be P = F*(x/t) = (4.7 N)*(x/t) = (4.7 N)*(7.1 kg)/t = (33.37 N·kg)/t = 33.37 J/s = 33.37 Watts.

In summary, the power delivered by a force of 4.7 N acting on a 7.1 kg object can be calculated using the equation P = F*v or P = F*(x/t) where x is the distance traveled and t is the time. In this case, the power is 33.37 Watts. I hope this nudges you in the right direction. Remember to always identify your known and unknown values and use the appropriate equations to solve the problem.