Does greater instantaneous velocity mean greater acceleration ?
Two cars are moving in the same direction in parallel lanes along a highway. At some instant, the instantaneous velocity of car A exceeds the instantaneous velocity of car B. Does this mean that car A's acceleration is greater than car B's ? Explain, and use examples.
This is a high school physics question.
I think car A's acceleration is greater than car B's acceleration at the instant car A's instantaneous velocity is greater than car B's instantaneous velocity. Car A's average acceleration may not be greater than car B's average acceleration.
Am I correct ?
This is a high school physics question.
I think car A's acceleration is greater than car B's acceleration at the instant car A's instantaneous velocity is greater than car B's instantaneous velocity. Car A's average acceleration may not be greater than car B's average acceleration.
Am I correct ?
ozo
No
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No, because acceleration is the rate of change in velocity, not the velocity itself. If one car is going faster than the other, then yes, the instantaneous velocity may be greater, but the rate of change in velocity may be exactly the same.
Without additional details, no answer can be given. For example, the cars may just be moving at constant speed, i.e. both have zero acceleration. That way, if at time T, the instantaneous velocity of A exceeds that of B, then it will do so at all other times as well.
Acceleration is only the change in velocity. If they are both going at a constant velocity and A happens to be going faster, then No, their acceleration is the same, zero, because their individual speeds are not changing.
If car B accelerates to 50 miles per hour then stays at that speed, car A can wait a while then accelerate to 100 miles per hour and stay at that constant speed and pass car B. If they are both traveling at their own constant velocities, the acceleration for both is 0. Zero.
If car B accelerates to 50 miles per hour then stays at that speed, car A can wait a while then accelerate to 100 miles per hour and stay at that constant speed and pass car B. If they are both traveling at their own constant velocities, the acceleration for both is 0. Zero.
Thanks, ozo for your succinct and correct answer. :-)
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>> the instantaneous velocity of car A exceeds the instantaneous velocity of car B. Does this mean that car A's acceleration is greater than car B's ? Explain, and use examples
for example
for example
if car A's acceleration is 0 and car B's acceleration is > 0, then, since acceleration is the change in velocity, car B will eventually have a greater instantaneous velocity than car A, if nothing else changes!
Ozo: Consider "the instantaneous position of car A exceeds the instantaneous position of car B. Does this mean that car A's velocity is greater than car B's ? "
A clear giveaway: "instantaneous". :-)
A clear giveaway: "instantaneous". :-)
ASKER
>> Does this mean that car A's acceleration is greater than car B's
Is question asking about instantaneous or average acceleration ?
Is question asking about instantaneous or average acceleration ?
ASKER
>> Consider "the instantaneous position of car A exceeds the instantaneous position of car B. Does this mean that car A's velocity is greater than car B's ? "
Is the question asking about instantaneous velocity or average velocity ?
Is the question asking about instantaneous velocity or average velocity ?
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All the above comments apply to the question about instantaneous position too. You can tell nothing about the velocity from the position. Maybe the one car started way over there.