Which of the solids investigated could be used to make a hand warmer? Describe soenbof the critical characteristics an ionic solid myst have to be used in the design of an effective hand warmer

Iron and vermiculite.

Explanation:

Iron and vermiculite are the solid substances used to make a hand warmer. Hand warmers contains iron, water, activated carbon, vermiculite, cellulose, and salt. The high melting, boiling points, hard and brittle are the characteristics of an ionic solid used in hand warmer. Iron is the ionic solid which is used in the hand warmer. Once iron exposed to air, the iron oxidizes and releases heat in the process.

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.