A soccer ball with a mass of 0.45 kg is kicked and is moving at 8.9 m/s. Find the kinetic
energy of the ball.

17.82J

Explanation:

Kinetic energy = 1/2 mv^2

Given

Mass M = 0.45kg

Velocity v = 8.9m/s

Therefore,

K.E. = 1/2 x 0.45 x (8.9)^2

= 1/2 x 0.45 x (8.9 x 8.9)

= 1/2 x 0.45 x 79.21

Multiply through

= 35.6445/2

= 17.82J

The kinetic energy of the ball is 17.82J

  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

b.

hope this : )