example force. because you can say" I applied 3 newtons downward to the floor".
force has magnitude and direcion
Answer:
Part a)

Part b)

Explanation:
Part a)
As we know that electric field intensity due to some given charge distribution is given as

now electric flux through a spherical surface of radius r is given as


now by Guass law we know that


now volume charge density is given as


Part b)
Total charge inside the radius R is given as

were solving for v velocity of the ball after it has hit the bottle. a. momentum ->p=mv->ball + bottle momentum during hit = ball + bottle momentum after hit-> ball (.5*21)+ bottle (.2*0) (it's 0 because the the bottle is standing still) = ball after hit (.5*v)+bottle after hit (.2*30) -> 10.5+0=.5v+6 ->4.5=.5v->v=9m/s
b. if bottle was heavier the ball would be slower so final velocity would decrease
Free fall without air resistance:
g=9.81 m/s²
t=235 s
h=?
h=0.5*g*t²
h=0.5*9.81*235²
h=270879m =270 km