Answer:
0.765m
Step-by-step explanation:
gravitational potential energy GPE = mass * acceleration due to gravity * height
Given
GPE = 30Joules
Mass m = 4kg
acceleration = 9.8m/s²
Required
Height h
From the formula
h = GPE/mg
h = 30/4(9.8)
h = 30/39.2
h = 0.765m\
Hence the height of the counter is 0.765m