Sound of thunder is heard 5s after the flash of lighting is seen. calculate the distance of nearest point of lighting if the speed of sound in air is 346 ms-1

formula

speed = distance / time

distance = speed x time

distance = 346 x 5

distance = 1730 m

The distance of the lightening strike would be 1730 m or 1.7 km

Explanation:

Part a)

cost = $35.58

Part b)

cost = $8.89

Explanation:

Part a)

Annual cost of the incandescent light bulb

Power = 100 Watt

daily use = 7.5 hours

total use of one year

cost of energy = $0.13 per kWh

so total cost of energy = $0.13 (273.75)

cost = $35.58

Part b)

25 watt fluorescent bulb

Power = 25 Watt

daily use = 7.5 hours

total use of one year

cost of energy = $0.13 per kWh

so total cost of energy = $0.13 (68.437)

cost = $8.89