To be safe during a lightning storm, it is best to be a. on a metal observation tower. b. inside a metal car. c. inside a wooden building without any grounding. d. in the middle of a grassy meadow. e. next to a tall tree in a forest.

Lightning and thunder occur when an electric field is generated between the cloud and the earth. When there are opposite charges, electricity travels through them and generates what we visually see as lightning and auditory we hear as thunder.

For the particular case of the meadow, there is not only direct conduction between the floor (which is full of water) and the sky, but also an individual is the only 'tall' object that can reach thunder more easily.

In the case of the tree, although it is taller, it is vulnerable to thunder falling there and it can fall on the person or be injured.

The tower is made of metal, which is a direct conductor of electricity that will expose the person in contact with it.

The wood construction might be ideal, but the floor could be damp, and remember that water is a conductor of electricity that could bring us electricity.

The car acts as an insulator for its tires and also serves as a capsule. It cuts the flow between heaven and earth which would allow it to serve as a good refuge.

Therefore the correct answer is B.

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:

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form