How much heat is released when 50.0 g of ethanol cools from 90 °c to 79 °c?

1100 J.

Explanation:

c of ethanol (gas) is 2.0 J/g°C.

Q = m.c.ΔT.

where, Q is the amount of heat released from ethanol cooling,

m is the mass of ethanol (m = 50.0 g),

c is the specific heat of ethanol in the gas phase (c = 2.0 J/g °C),

ΔT is the temperature difference (final T - initial T) (ΔT = 79.0 °C – 90.0 °C = - 11.0 °C).

∴ Q = m.c.ΔT = (50.0 g)(2.0 J/g °C)(- 11.0 °C) = - 1100 J.

The system releases 1100 J.

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.

gas

explanation:

smoke is the matter of a gas