Here... I've finished this course already
Speed can be measured by bouncing waves off an object, because of the Doppler Effect.
The surge protector doesn't use energy. The current that carries Energy may pass through it but a good surge protector won't consume any of that energy. It'll just pass through the surge protector. The current that carrys the energy passes through it to be used by devices further on down the line, such as a toaster or a welder. If those devices are using 1.8 kilowatts of power, then that means that 6,480,000 Joules of energy pass through the surge protector in one hour. They all come out the other end and keep going.
Answer:
If a neutral atom gains electrons, then it will become negatively charged. If a neutral atom loses electrons, then it become positively charged.
lf a heavy point mass is suspended by a weightless, inextensible and perfectly flexible string from a rigid support, then this arrangement is called simple pendulum.
In practice, however, these requirements cannot be fulfilled. So we use a practical pendulum.
A practical pendulum consists of a small metallic solid sphere suspended by a fine silk thread from a rigid support. This is the practical simple pendulum which is nearest to the ideal simple pendulum.
Note :
The metallic sphere is called the bob.
When the bob is displaced slightly to one side from its mean position and released, it oscillates about its mean position in a vertical plane.