How do you express 78,000 in scientific notation?

7.8 x 103

7.8 x 104

7.8 x 10-4

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide

1) estimating temperature to the nearest tenth of a degree

2) estimating the mass of the sample to the nearest tenth of a gram

4) the position of the cups of sand and water under the heat lamp

answer: the potential energy decreases from 379 j to 243 j

explanation:

for the law of conservation of energy, the total energy in a system must be conserved. the total energy of the system is given by the sum of kinetic (k) and potential (u) energy:

e = k + u

the total energy is e=675 j, and this does not change.

initially, the kinetic energy is k=296 j, so the potential energy is

at the end, the kinetic energy is k=432 j, so the potential energy is

so, we see that the potential energy has decreased from 379 j to 243 j.