Answer:
The answer to this question is False
I do not agree with the statement.
The "substance" can be a compound. It's "pure"
as long as there's nothing else in it but its name.
'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.
These example substances are all compounds, not elements.
It’s solved by using a pretty standard formula for efficiency.
When an object moves its length contracts in the direction of motion. The faster it moves the shorter it gets in the direction of motion.
The object in this question moves and then stops moving. So it's length first contracts and then expands to its original length when the motion stops.
The speed doesn't have to be anywhere near the speed of light. When the object moves its length contracts no matter how fast or slow it's moving.
Answer: B. If an object's velocity is changing,it's either experiencing acceleration or deceleration.
Acceleration is defined as the rate at which an object changes its velocity. This implies that if an object is changing it's velocity it is experiencing acceleration/ deceleration.
Acceleration is a vector quantity that has both a magnitude and time.
It is represented as
Acceleration= change in velocity/time.
The SI unit for acceleration is m/s^2
