ElectricPavlov

Well... she needs   2/5 +3/4    =   8/20 + 15/20 = 23/20 to do her jobs.

IS 7/6   greater than or equal to her needs of 23/20 ???

7/6 =  70/ 60  >= ? 23/20 ?

70/60 >= 69/60        Yep   ....she has just barely enough!

mgh = energy of hammer delivered to pile = 150*9.8*5 = 7350 j

Amount delivered to the pile  400kg x 9.8 x .0075=400*9.8*.0075 = 29.4 j

The difference is delivered to the ground (vibrations, ground movement, heat of friction etc) and is the resistance (?)

7350-29.4 = 7320.6 j

(a little unsure)

That is true...I used a slide rule back then !   Really....

First....look in the Lower Left corner to make sure the calculator is set to ' deg'

then sin = opp/hyp = 4.5/11.75 = .382978

The press the ' 2nd ' key on the calculator then the ' asin ' key ....which is arc sin  which is sin inverse...

= 22.52 degrees

-11  - 2/3   =   -11 2/3 = -35/3 = -11.6666667

I think we will not know until the Universe ends......   and then there will be nobody around to know...    

  sorry......well, kind of sorry !

No...the E means the exponent of 10   so it would be 3.76375 x 10^22      NOT 10^25

Tan x = .0563

ARCtan(x) = x = Arctan(.0563) =3.222 degrees =.0562 R

2x+11=-19-3x     First let's add 3x to both sides to get

5x +11 = -19       then subtract 11 from both sides

5x = -30               then divide both sides by 5

x = -6

P= 9^x

Log P = x log 9

Log P/Log 9 = x

1.04795 Log P = x      SUb this into the second equation

3^(2x) +3

3^(2(1.04795 LogP)) +3

3^(2.0959 Log P)  + 3