DYNAMICS Using the link below please solve all of number 4 P

(DYNAMICS) Using the link below please solve all of number 4. Please solve step by step and neatly so i may fully understand with formulas used. Thank you! Also if u have a hard time reading it you can copy and paste into word and zoom in. Thank you.

http://imgur.com/6ipRMo1

Solution

1. (a)
gravitational PE = m g h = 15 x 9.8 x 0.62

          = 91.14 J

(b) using energy conservation,

mgh = mv^2/2

v = sqrt(2 gh) = 3.49 m/s

c) Using energy conservation.

m g h + 0 + 0 = - m g d + kd^2/2 + 0

125000 d^2 - 147d - 91.14 = 0

d = 0.0276 m Or 2.76 cm