What is the time lapse between seeing a lightning strike and hearing the thunder if the lightning flash is 47 km away? The speed of light waves in air is 3 × 108 m/s and the speed of sound waves in air is 333 m/s.

141.14098 secs

Explanation:

Time taken to see the lightning flash can be gotten from:

Velocity = distance/time

Time = distance/velocity

Time = (47 * 1000)/(3 * 10^8)

Time = 0.0001567 secs

Time taken to hear the thunder can be gotten from:

Velocity = distance/time

Time = distance/velocity

Time = (47 * 1000)/(333)

Time = 141.14114 secs

The time lapse between the lightning flash and the thunder will be:

141.14114 - 0. 0001567

= 141.14098 secs

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

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