Answer:
A. Acceleration always involves changing speed.
Explanation:
Acceleration is defined as the rate of change of velocity.
Velocity is a vector quantity and is defined as speed in a given direction. Therefore, when any or both of the components of velocity is changing with time, a body is said to be accelerating i.e. acceleration involves a change of speed or change in direction, or a change in both speed and direction.
Considering the statements:
A. Acceleration always involves changing speed is false because acceleration can occur when speed is constant but direction is changing.
B. Changing direction always involves acceleration is true because, a change in direction results in a change in velocity.
C Changing speed always involves acceleration is true because, changing speed results in a change in velocity.
D. Circular motion always involves acceleration is true because in circular motion the direction is always changing, and this results in a change in velocity
Answer: yes u can use a 6.75 when measuring the pencil
The shape of Earth's lithosphere is continually changing. Bedrock that is closer to oceanic ridges is younger in age than bedrock that is farther away. What can best be concluded from this information? It can cause pollution of water in lakes and rivers
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
