A 4lb ball is travelling in a circle radius 3ft speed 6ft/s. the attached cord pulled through the center has constant speed 2ft/s. how much time for the ball to reach 12 ft/s

Explanation:

Circle motion

Weight=4lb

Radius=3ft

Velocity Vb= 6ft/s

Velocity Vr=2ft/s

Velocity Vo=12

V2=√Vo²+Vr²

12=√Vo²+2²

Square both side

144=Vo²+4

Vo²=140

Vo=11.83ft/s

Applying conservation of angular momentum

Ha1=Hb2

MbVbr1=MbVor2

r2=Vbr1/Vo

r2=6×3/11.83

r2=1.52ft

The require time is written as.

∆r=Vrt

t=∆r/Vr

t=r1-r2/Vr

t=3-1.52/2

t=0.74sec

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz

it is a negative acceleration