We cannot feel speed. But our senses let us know that we are moving. We see things moving past us and feel that we are being shaken.
We can feel acceleration, an increase in speed. But we notice it for only a short time. For instance, we fell it during the takeoff run of an airliner.
We feel the plane’s acceleration because our bodies do not gain speed as fast as the plane does. It seems that something is pushing us back against the seat. Actually, our bodies are trying to stay in the same place. While the plane is carrying us forward.
Soon the plane reaches a steady because there is no longer any change in speed, the feeling of forward motion stops.
1. We can tell that we are moving by _____.
A. watching things move fast
B. feeling the speed
C. feeling shaken
D. both A and C
2. Acceleration is the name of _____.
A. an increase in speed
B. a steady speed
C. any kind of movement
D. the movement of a plane
解析： We can feel acceleration, an increase in speed.
3. During the takeoff of a plane, we feel that we are being _____.
A. thrown forward
B. pushed back against the seat
C. lifted out of the seat
D. pushed down into the seat
4. We feel the plane’s acceleration because our bodies gain speed _____.
A. just as fast as the plane
B. faster than the plane
C. more slowly than the plane
D. before the plane
5. This feeling stops when _____.
A. the plane stops climbing
C. there is no longer any change in speed
D. we begin to feel speed