Question #5b412
1 Answer
In general velocity is not directly proportional to time.
Explanation:
Velocity would be directly proportional to time only if the initial velocity (at time
Example with initial velocity zero and fixed rate of acceleration:
Suppose a ball is dropped from a very high cliff.
Ignoring air resistance and other minor factors:
- the ball has an initial velocity of 0 (at time 0)
- the ball accelerates at a rate of
- after 1 second, its velocity will be
- after 2 seconds, its velocity will be
- and so on.
Example with non-zero initial velocity (but fixed rate of acceleration):
Suppose the ball was thrown towards the ground below the cliff (see above example) with an initial velocity of
because of the acceleration due to gravity:
- after 1 second the ball would have a velocity of
- after 2 seconds the ball would have a velocity of
Obviously there is no direct proportion, in this case, between the time and the velocity.
One more example:
Think about what happens when you make a typical trip in a car.
Maybe you drive away from your home at some fairly steady velocity; say