A plastic pipe is negatively charged. What can be inferred about the number of protons and electrons in the plastic pipe ?

Initial velocity,  u = 4.9 m/sfinal velocity = v m/sinitial height,  h₁ =  245 m    final height, h₂ = 0a = -9.8  m/s²time taken = t secondss = ut + 0.5at²⇒  (h₂-h₁) = ut + 0.5at²⇒  0-245 = 4.9t + 0.5×(-9.8)×t²⇒ -245 = 4.9t - 4.9t²⇒ 4.9t² -4.9t -245 =0solving it, we get   t = 7.59sv  = u +  at = 4.9 -9.8×7.59 = 4.9 - 74.38 = -69.48 m/svelocity is  69.48 m/s downward

Sound wavelength of visible light waves

Idont know because i dont see a pic of it

The answer is  the gravitational potential energy it had from being above the ground is converted to kinetic energy as the rock falls. as kinetic energy increases, the velocity of the rock will also increase. however, if one considers the air, the rock will lose energy as it falls due to air resistance. if the cliff is high enough, the acceleration due to gravity and the air resistance due to the velocity will be exactly equal and there will be no change in kinetic energy.  hope its and mostly important have a nice day ; )