Question

A 5.0 kg toy car can move along an x axis, figure below givesof the force acting on the car, which begins at rest at timet 0. The scale on the raxis is set bys 5.0 N. In unit-vector notation, what isPat (a) t 4.0 s and (b) t-7.0 s, and (c) what isvatt- 9.0 s?

please write out formulas as if i have no idea about physics. i know that this is a collision & impulse problem.

Answer 1

Change in momentum = impulse provided = Fdt = Area under curve.

p_(t=0) = 0

a)

p_(t=4) = p_(t=0) + impulse = 0 + 0.5*2*10 + 10*2

p_(t=4) = 30 kg.m/s

b)

p_(t=7) = 0.5*2*2*10 + 10*2 - 0.5*1*5

p_(t=7) = 37.5 kg.m/s

c)

p_(t=9) = 0.5*2*2*10 + 10*2 - (2*0.5*1*5 + 5*1)

p_(t=9) = 30 kg.m/s

v = 30/5 = 6 m/s