An object, which is initially at rest on a frictionless horizontal surface, is a
ID: 1447238 • Letter: A
Question
An object, which is initially at rest on a frictionless horizontal surface, is acted upon by four constant forces. F_1 is 25.1 N acting due East, F_2 is 32.8 N acting due North, F_3 is 47.8 N acting due West, and F_4 is 10.8 N acting due South. How much total work is done on the object in 4.44 seconds, if it has a mass of 16.0 kg? Which type of energy is changing for the object while the above work is being done? internal energy gravitational potential energy kinetic energy elastic potential energy How fast does the object end up moving at the end of the 4.44 seconds?Explanation / Answer
Net northery force, F(n) = F2 - F4 = 32.8-10.8 = 22 N
Net westerly force, F(w) = F3 - F1 = 47.8-25.1 = 22.7 N
Resultant force, F(r) = sqrt(F(n)^2 + F(w)^2) = sqrt(22^2+22.7^2) = 31.61 N
acceleration = 31.61/16 = 1.98 m/s^2
distance d = 1/2at^2 = 1/2*1.98*4.44^2 = 19.52 m
work = f*d = 31.61*19.52 = 617.027 J
kinetic energy