Can anyone plz give me a right answer now?

Dy = - 0.0789 [m]

Explanation:

The vertical component of the vector can be determined with the sine of the angle.

Dy = 0.250*sin(18.4)

Dy = 0.0789 [m]

As the y-component is pointing downwards the component is negative.

Dy = - 0.0789 [m]

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

i think the answer would be reserve.