a 2 kg object moving at 5 m/s enters a surface with the coefficient of kinetic friction is .1 and is brought to a full stop. If the cart moved 12.8 m calculate:
a) the net work done on the object over the 12.8 m distance (I got 6.4j, but it's probably wrong)
b) change in kinetic energy of the object
c) in what form of energe was the kinetic energy changed?
Net work=mu*m*g*distance
change KE=KEinitial-KEfinal=KEinitial-0
friction results in heat.
To find the answers to the given problem, we will use the concepts of work, friction, and kinetic energy. Let's break it down step by step:
a) The net work done on the object is equal to the change in kinetic energy of the object. According to the work-energy theorem, the work done on an object is equal to the change in its kinetic energy.
We can calculate the net work done using the following formula:
Net work = Change in kinetic energy
Change in kinetic energy = Final kinetic energy - Initial kinetic energy
Since the object comes to a stop, the final kinetic energy is zero. The initial kinetic energy can be calculated using the formula:
Initial kinetic energy = (1/2) * mass * (velocity)^2
Plugging in the values, we get:
Initial kinetic energy = (1/2) * (2 kg) * (5 m/s)^2
Initial kinetic energy = 25 J
Therefore, the net work done on the object is:
Net work = Change in kinetic energy
Net work = Final kinetic energy - Initial kinetic energy
Net work = 0 J - 25 J
Net work = -25 J
So, the net work done on the object over the 12.8 m distance is -25 J, not 6.4 J.
b) The change in kinetic energy of the object can be calculated using the formula:
Change in kinetic energy = Final kinetic energy - Initial kinetic energy
Since the final kinetic energy is zero, the change in kinetic energy is:
Change in kinetic energy = 0 J - 25 J
Change in kinetic energy = -25 J
Therefore, the change in kinetic energy of the object is -25 J.
c) In this case, the kinetic energy of the object is changed to another form of energy, specifically, thermal energy. As the object comes to a stop, the kinetic energy is converted to heat due to the friction between the object and the surface.