Ababy stroller is a rest on top of a hill which is 10 m high. the stroller and baby have a mass of 20 kg. what is the potential energy of the baby and stroller? formula: pe = m g h (gravity near earth is 9.8 m/s²)

Potential energy (PE) = mgh

mass of stroller and baby  = 20 Kg

PE = 20 Kg x 9.8m/s^2 x 10 m

= 1960 kg m^2/s^2

a- all cells come from pre-existing cells

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.