15 J of work were expended moving an 18 kg block. At what velocity did the block move?

√(5/3)m/s

Explanation:

Kinetic energy(ke)=15j

Mass(m)=18kg

Velocity(v)=?

Ke=(mxv^2)/2

15=(18xv^2)/2

Cross product

(18xv^2)=15x2

18xv^2=30

Divide both sides by 18

(18xv^2) ➗ 18=30 ➗ 18

v^2=5/3

v=√(5/3)

v=√(5/3)m/s

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.