Answer:
C. At a particular instant
Explanation:
Speed is the defined as the ratio between the distance covered by an object and the time taken:

where d is the distance and t the time.
However, there are two possible measurements of speed:
- Average speed: this is the speed measured over a non-zero time interval (for example: a car moving 100 metres in 5 seconds; its average speed is

- Instantaneous speed: this is the speed of an object measured at a particular instant in time, so for a time interval that tends to zero. So, in the previous example, the average speed is 20 m/s but the instantaneous speed of the car at various instants of time can be different from that value.
Answer:
it becomes a gas
Explanation:
the matter expands, turning into steam, a gas.
Answer:
v= s/t
Explanation:
250 km/ h =69.44m/s
S1=2 times 69.44 ≈ 139m
Next 2.5 seconds:
S2 = 100m
Average speed:
v=139m+100m/2s+2.5s = 239/4.5s = 53.2 m/s=192km/h
Are there any options??
I would have to say metal of course but without options I can't assume anything