9. A football punter attempts to kick the football so that it lands on the ground 67.0 m from where it is kicked and stays in the air for 4.50 s. At what angle and with what initial speed should the ball be kicked? Assume that the ball leaves the punker’s foot at a height of 1.23 m.

Angle is 55.52°

and Initial Speed is v=26.48 m/s

Explanation:

Given data

Applying the kinematics equations for motion with uniform acceleration in x and y direction

So

Put the value of v₀ from equation (1) to equation (2)

So

Put that angle in equation (1) or equation (2) to find the initial velocity

So from equation (1)

  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