A rock falls from a tower that is 320 feet high. As it is falling, its height is given by the formula h equals 320 minus 16 t squared . How many seconds (in tenths) will it take for the rock to hit the ground (hequals0)?

a. 4.5secs

Explanation:

From the question, the equation describing the height is given by

at the point when the rock hit the ground, the height,h will be zero.

Hence we can have

hence the rock will hit the ground in 4.5secs

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j