The density of a substance is its mass per unit volume. 
a. give a possible metric unit for density. 
b. is the unit for density base or derived?  

Asoccer ball of mass 0.43 kg is rolling with velocity < 0, 0, 1.8> m/s, when you kick it. your kick delivers an impulse of magnitude 2.7 nâ·s in the direction. the net force on the rolling ball, due to the air and the grass, is 0.22 n in the direction opposite to the direction of the ball's momentum. using a time step of 0.5 s, find the position of the ball at a time 1.5 s after you kick it, assuming that the ball is at the origin at the moment it is kicked. use the approximation . (express your answer in vector form.) < entry field with incorrect answer 12.97 , entry field with correct answer 00 , entry field with incorrect answer 2.7 > m