Ahiker treks 30 degrees south of east at a speed of 15 m/s for 30 min and then turns due west and hikes at a speed of 8m/s for another 20 min. what is the displacement of this explorer (magnitude and direction)?

19.3 km, south of east

Explanation:

Given

Hiker treks south of east at a speed of 15 m/s for 30 min and then turns due to west and hikes at speed of 8 m/s for another 20 min

Let position vector of Hiker at the end of 30 min

after he turns west so new position vector of hiker is

Therefore Displacement is given by |r'|

for direction

south of east

it may be wrong but i think its a

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.