Question

which of the following best describes acceleration

*These are not the answer choices*
1. an object speeding up
2. an object slowing down
3. an object changing in direction
4. an object that is at rest

*these are the answer choices*

All of the choices describe acceleration
1 and 2
1 and 3****
1, 2, and 3

Answer 1

Speed is a scalar. You an measure it with a speedometer.
BUT
Velocity is a VECTOR. You need both the speedometer AND a compass.

Acceleration is a vector, rate of change of Velocity
THEREFORE
If speed changes, that is Acceleration
ALSO
If direction changes, that is acceleration.
NOW
1. Speeding up = acceleration
2. Speed down = acceleration
3. changing direction = acceleration
4. No change in speed, no change in direction, no acceleration.

Answer 2

Thank you so much Damon!! Have a great day!!

Answer 3

You are welcome. By the way if you have learned about "centripetal acceleration", that is acceleration with no speed change, just direction.

Answer 4

I haven't learned about that yet, but thank you for telling me! Now when that lesson comes up I'll already have an idea about what it is.

Answer 5

Good :) and acceleration can be + or -. Often if negative it is called de-acceleration but not by physicists :)

Answer 6

the answer is (the runner slowing down at the end of the race) yw :>)