They use Newton to measure force
Answer:
B. a piece of paper being torn
Explanation:
A chemical change is one that cannot be reversed. This means the original properties of the substance or object cannot be restored.
If you cook a raw egg, it would turn into a boiled egg (or a poached egg, however it is being cooked). The reaction is irreversible, so you cannot turn the cooked egg back into a raw egg - it is basically impossible to 'uncook' an already cooked egg.
When you toast a piece of bread, it turns into toast. You can't 'untoast' it back into bread. The chemical changes have already occurred and cannot be undone.
If you tear a piece of paper, it is still paper. You are only ripping it, not changing anything about it. You could simply tape the torn bit back to the original bit, or glue it - either way, it is still paper and nothing has occurred to drastically change the physical state of it.
Therefore, B is not a chemical change.
Answer:
Current is in phase with voltage in a resistive circuit. Note that the wave form for power is always positive, never negative for this resistive circuit. This means that power is always being dissipated by the resistive load, and never returned to the source as it is with reactive loads.Explanation:
Answer: True
Explanation:
Pencils indeed should not be used as tools when working inside a computer because it is made of Lead.
Lead is a conductor of electricity and as such if it is left inside the computer at even miniscule quantities, it can redirect electricity and damage components in the process.
If one wants to work inside a computer, it is best to use tools like tweezers and needle-nose pliers.
Answer:
(a) 9.36 kHz
(b) 3.12 kHz
Explanation:
(a)
V = speed of sound
= speed of airplane = (0.5) V
f = actual frequency of sound emitted by airplane = 4.68 kHz = 4680 Hz
f' = Frequency heard by the stationary listener
Using Doppler's effect
f' = 9360 Hz
f' = 9.36 kHz
(b)
V = speed of sound
= speed of airplane = (0.5) V
f = actual frequency of sound emitted by airplane = 4.68 kHz = 4680 Hz
f' = Frequency heard by the stationary listener
Using Doppler's effect
f' = 3120 Hz
f' = 3.12 kHz
