Q9
Q11
Q13
Q20
Q21
q29
q9 change in momentum =m(v-u)=0.1(20--30)=5 B
11)A the deeper you go, the greater the pressure
13)c 0.2*900=0.6*F
20)Y=Fl/Ae so F=YAe/l double the length means half the force and half the area means half the force
Acos 1/2*1/2=1/4
21)1/2*.3*12=1.8 A
29)d conservation of energy 1/2mv^2=qV=qEx