Problem 2: The only force acting on a 5kg object has components Fx = 15N and Fy = 25N. Find the acceleration of the object.
Solution. m = 5kg Fx = 15N, Fy = 25N F = Fxi + Fyj
= √ 225 + 625 = √850 F = ma Or, a = F / m = √850 / 5 = 5 √34 / 5 = √34 = 5.83m / s 2
Impulse o Impulse is defined as a force multiplied by time it acts over. o
For example: Tennis racket strikes a ball, an impulse is applied to the ball. The racket puts a force on the ball for a short time period.
F ∆t = ∆p F = ∆p / ∆t = Rate of Change of momentum