Answer: 8.81 J
Explanation: The scalar or dot product of 2 vector equals the product of the magnitude of both vectors and the cosine value of the angle between them
Magnitude of vector f (force) as given in the question = 12.5N
Magnitude of length = 0.75m
Angle between vectors = 25°
F. Δr = 12.5 * 0.75 * cos 25
F. Δr = 12.5 * 0.75 * 0.9063
F. Δr = 8.81 J
Well its C, cant show you the work its in my head sorry.
Kinetic energy= .5 x m x v^2
KE=.5 x 4.2 x 3.85^2
KE=31.13