Evelyn walked to the store a distance of 1.6 km in 30 min. What is her average speed in m/s?

Average speed = (distance covered) / (time to cover the distance)

Average speed = (1.6 km) / (30 min)

Average speed = 0.0533 km/min

This is the true average speed, but it's not in the units that the question asked for.  So we have to massage it and convert it to ' meters/sec '.

Speed = (1.6 km) / (30 min)

Speed = (1.6 km / 30 min) x (1,000 m / 1 km) x (1 min / 60 sec)

Speed = (1.6 x 1,000 x 1) / (30 x 1 x 60) (km-m-min / min-km-sec)

Speed = (1,600 / 1,800) (m / sec)

Speed = 0.89 m/s    

the results is a decrease in air temperature with an increase of altitude.

explanation:

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000