A force of 20 N is applied horizontally to a 1 kg mass on a level surface. The coefficient of friction is .2. if the mass is moved a distance of 5m what is the change in KE?
W= change in Ke
Fd= Change in KE
(20)(5)=Change in Ke
200 J =change in Ke
But the thing is how would I incorporate friction since it acts on the mass and the surface? F_f= Fn(meu)
=mg(meu)
=1(9.8)(.2)
=1.96 N
Would i just subtract 1.96N and 20N ?
You almost have it.
Netforce*distance= changeinKE
(20-mu*1*9.8)*5=change in ke
or, you could calculate work in (your Fd) and subtract friction work. You forgot the distance on your fricion calcs.
To incorporate friction in this problem, you need to first calculate the force of friction acting on the mass. The force of friction can be found using the equation:
Frictional force (F_f) = Normal force (Fn) * Coefficient of friction (μ)
In this case, the normal force (Fn) is equal to the weight of the mass, which is the product of mass (m) and gravity (g). So, Fn = m * g.
To find the force of friction, you can substitute the values:
Fn = 1 kg * 9.8 m/s^2 = 9.8 N
F_f = Fn * μ = 9.8 N * 0.2 = 1.96 N
The force of friction acting on the mass is 1.96 N.
Next, you can calculate the net force acting on the mass by subtracting the force of friction from the applied force:
Net force (F_net) = Applied force (F_applied) - Frictional force (F_f)
F_net = 20 N - 1.96 N = 18.04 N
Finally, you can calculate the change in kinetic energy (ΔKE) using the equation:
ΔKE = Force * distance
ΔKE = F_net * distance = 18.04 N * 5 m = 90.2 J
Therefore, the change in kinetic energy is 90.2 Joules.