Answer: Student 2
Explanation: Iron nail and a paperclip are conductors because they are made of metal. A rock, rubber band, and wooden stick are insulators because they cannot conduct electricity.
Power used by the clock=1.03 W
Explanation:
resistance= 14000 ohm
voltage=120 V
The formula for the power is given by
P=(120)²/14000
P=1.03 W
Answer:
D. infinitely extended in all directions
Explanation:
A semi infinite solid is infinitely extended in every direction. It has a single surface and can extend when heat is applied.
The body of a semi infinite solid is idealised, that is, when there is heat present, it expands in all directions to infinity. It can be used for a thick wall because its shape can be changed when subjected to different levels of heat near its surface.
It is also expands as heat is applied because its thickness is negligible.
This idealized body is used for earth, thick wall, steel piece of any shaped quenched rapidly etc indetermining variation of temperature near its surface & other surface being too far to have any impact on the region in short period of time since heat doesn’t have sufficient time to penetrate deep into body thus thickness can be neglected
The 120 decibel sound has more amplitude than the 100 decibel sound.
In Physics, the relation between amplitude and intensity is that the intensity of the wave is directly proportional to the square of its amplitude.
Forces are balanced when net force on the object is zero or the sum of all force on the object is zero.
For book kept on a shelf, the weight of the book in down direction is balanced by the normal force on the book by the shelf. hence the book kept on a shelf is an example of balanced force.
In case of air rushing out of balloon , the balloon experience a net force by the air coming out of it.
rolling over and falling off the bed , the object falls under gravity force.
a car speeding up accelerates. since it accelerates , it has net force on it.
