4.1 A steel spur pinion has a pitch of 5 teeth/in, 20 full-depth teeth, and a 20° pressure angle. The pinion runs at a speed of 2000 rev/min and transmits 30 hp to a 50-tooth gear. If the face width is 1 in, estimate the bending stress.

15.07 ksi

Explanation:

Given that:

Pitch (P) = 5 teeth/in

Pressure angle () = 20°

Pinion speed ( ) = 2000 rev/min

Power (H) = 30 hp

Teeth on gear () = 50

Teeth on pinion () = 20

Face width (F) = 1 in

Let us first determine the diameter (d) of the pinion.

Diameter (d) =

=

= 4 in

From the values of Lewis Form Factor Y for ( ) = 20 ; at 20°

Y = 0.321

To find the velocity (V); we use the formula:

V = 2094.40 ft/min

For cut or milled profile; the velocity factor can be determined as follows:

= 2.0472

However, there is need to get the value of the tangential load, in order to achieve that, we have the following expression

Finally, the bending stress is calculated via the formula:

15.07 ksi

∴ The estimate of the bending stress = 15.07 ksi

  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

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