Question

Two forces, F1 (-3801+ 3.05j) N and F2 (-3 951+ 6.40j) N, act on a particle of mass 2.30 kg that is initially at rest at coordinates (+2.10 +255 m) (a) What are the components of the particle's velocity at t- 11.9 s? m/s (b) In what direction is the particle moving at t- 11.9 s? counterclockwise from the +x-axis (c) What displacement does the particle undergo during the first 11.9 s? (d) What are the coordinates of the particle at t11.9 s? x=

Answer 1

(a)

F1 = (-3.8i + 3.05 j) N

F2 = (-3.95i + 6.4j) N

Ff = F1 + F2

Ff = (-7.75i + 9.45j)

F = ma; -7.75 = 2.3a ====> ai = -3.4 m/s^2

F = ma; 9.45 = 2.3a =====> aj = 4.1 m/s^2

V = -3.4(11.9)i + 4.1(11.9)j

V = (40.46i + 48.79j) m/s

(b) Vector F = sqrt ( (-7.75)^2 + 9.45^2) = 12.2

      tetha = arctan (9.45/-7.75) = -50.6 degree

(c) Xf = Xi + VixT + 1/2AxT^2

     deltaX = 0+ 1/2(-3.4)(11.9)^2

     deltaX = -240.7 m

     Yf = Yi + ViyT + 1/2AyT^2

     deltaY = 0 + 1/2(4.1)(11.9)^2 = 290.3 m