Which of the following is the best definition of a physical change? A. Something that can be observed or measured while changing the identity of the substance.

B. A nail rusting.

C. A change that occurs without changing the identity of the substance.

D. Ice melting into water.

the answer is D.ice melting into water

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

its first and third is your answer i did the qustion the fourth isnt right