Answer: Often lightning occurs between clouds or inside a cloud. But the lightning we usually care about most is the lightning that goes from clouds to ground.
Explanation: As the storm moves over the ground, the strong negative charge in the cloud attracts positive charges in the ground.
It is c which is four minutes per day
Answer:
Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and mold spores may be suspended as particles. Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's also called smog.
Answer: a) angular acceleration(alpha)=-14.8rad/s^2
b) time taken (t) = 1.52s
Explanation:
What we are given
Mass of the solid sphere m =225g = 0.225kg
Diameter D = 3.00cm = 0.0300m
Radius = D/2 = 0.01500m
Frictional Force = 0.0200N
a) to determine the angular acceleration, we first calculate the torque, then moment of inertia, before the angular acceleration.
Torque = -fr
= - (0.0200)(0.01500)
=-3.00X10^-4Nm
Moment of inertia I
= 2/5mr^2
=2/5(0.225)(0.01500)^2
=2.025X10^-5kgm^2
Angular acceleration (alpha)= torque/moment of inertia (I)
= -3.00X10^-4Nm/2.025X10^-5kgm^2
=-14.8rad/s^2
b) time taken (∆t) = w/alpha
w= -22.5rad/s
Angular acceleration (alpha) = -14.8rad/s^2
∆t = -22.5/-14.8
= -1.52s
