A car has the same kinetic energy when it is traveling south at 30 m/s as when it is traveling northwest as when it is traveling northwest at 30 m/s. Is the momentum of the car the same in both cases

Explanation:

Kinetic energy is a scalar quantity and momentum is a vector quantity . Therefore , kinetic energy will remain unchanged even when the velocity changes direction if its magnitude remains same . But momentum will not remain same if direction  of velocity is changed even if magnitude remains unchanged.

In the given problem , magnitude of velocity remains unchanged but its direction has changed so its momentum will also change. A force must be acting on the car.

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.