Answer:
C) W = - 190 J
Explanation:
Notation
Wf = work done by the friction force (unknown)
Ff = force of the friction
d = distance travelled by the box = (2 pi 1.82 m) = 11.435 m
Kinetic energy is the energy possessed by a body while in motion. It is calculated by 1/2mv², where m is the mass of the body and v is the velocity.
Therefore, kinetic energy is dependent on both mass of the body and the velocity. An increase in mass increases the kinetic energy, an increase in velocity also increases kinetic energy of the body. Thus, doubling the mass and doubling the velocity will both increase the kinetic energy of the body.
distance traveled by a uniformly accelerated bike is given as
![d = \frac{v_f + v_i}{2} (t)](https://tex.z-dn.net/?f=d%20%3D%20%5Cfrac%7Bv_f%20%2B%20v_i%7D%7B2%7D%20%28t%29)
here we know that
![v_f = 25 m/s](https://tex.z-dn.net/?f=v_f%20%3D%2025%20m%2Fs)
![v_i = 15 m/s](https://tex.z-dn.net/?f=v_i%20%3D%2015%20m%2Fs)
![t = 15 s](https://tex.z-dn.net/?f=t%20%3D%2015%20s)
now we will have from above equation
![d = \frac{15 + 25}{2} (15)](https://tex.z-dn.net/?f=d%20%3D%20%5Cfrac%7B15%20%2B%2025%7D%7B2%7D%20%2815%29)
![d = 20 (15) = 300 m](https://tex.z-dn.net/?f=d%20%3D%2020%20%2815%29%20%3D%20300%20m)
so it will cover the total distance of 300 m