Question

positive velocity is when an object has speed in a blank direction. negative velocity is when an object has speed in a blank direction. positive acceleration is when the change in velocity has a blank difference. negative acceleration is when the change in velocity has blank difference. an example of an object with a negative velocity and a positive acceleration would be when a car brakes because the car is blank but is still moving forward.

Answer:

To solve this fill - in - the - blank problem about velocity and acceleration, we analyze each blank based on the concepts of velocity (a vector quantity with magnitude and direction) and acceleration (the rate of change of velocity):

1. Positive velocity direction

Velocity is positive when an object moves in the forward (or a pre - defined positive, like right - ward, upward depending on the coordinate system) direction. So the first blank (for positive velocity direction) is filled with "forward".

2. Negative velocity direction

Velocity is negative when an object moves in the backward (opposite to the positive direction, like left - ward, downward) direction. So the second blank (for negative velocity direction) is filled with "backward".

3. Positive acceleration velocity change

Acceleration is positive when the change in velocity (final velocity - initial velocity) is positive. This means the final velocity is greater than the initial velocity, so the change in velocity has a positive difference. So the third blank (for positive acceleration's velocity change difference) is filled with "positive".

4. Negative acceleration velocity change

Acceleration is negative when the change in velocity (final velocity - initial velocity) is negative. This means the final velocity is less than the initial velocity, so the change in velocity has a negative difference. So the fourth blank (for negative acceleration's velocity change difference) is filled with "negative".

5. Car with negative velocity and positive acceleration (brakes situation)

When a car brakes, if we consider the forward direction as positive, the car is still moving forward (so velocity is positive? Wait, maybe there is a mix - up. Wait, if the car is braking but still moving forward, its velocity is positive (since it's moving in the forward direction), but its acceleration is negative (because it's slowing down). Wait, the problem says "an object with a negative velocity and a positive acceleration". Maybe the coordinate system is such that the object is moving backward (negative velocity) but speeding up backward? No, the example given is a car with brakes. Wait, maybe the problem has a typo, but following the blank: when a car brakes, if we consider the velocity as positive (moving forward) and acceleration as negative (slowing down). But the problem says "negative velocity and positive acceleration". Maybe the car is moving backward (negative velocity) and accelerating backward? No, positive acceleration would be in the direction of velocity. Wait, maybe the blank is about the car's state. When a car brakes, it is slowing down (but still moving forward). So the blank for the car's action when it has negative velocity (maybe moving backward) and positive acceleration (speeding up backward) is not. Wait, the sentence is "An example of an object with a negative velocity and a positive acceleration would be when a car brakes because the car is [blank] but is still moving forward." Wait, if the car is braking, it's slowing down. But if velocity is negative (moving backward) and acceleration is positive (speeding up backward), but the car is moving forward? No, maybe the problem has a mistake. But based on the common braking situation (moving forward, positive velocity, negative acceleration), but the problem says negative velocity and positive acceleration. Maybe the blank is "slowing down" (but that's for positive velocity and negative acceleration). Alternatively, if we take the problem as is, maybe the blank is "speeding up" (but that contradicts braking). Wait, maybe the problem is trying to say: when a car has negative velocity (moving backward) and positive acceleration (speeding up backward), but it's still moving forward? No, that doesn't make sense. Maybe the correct answer for the last blank is "slowing down" (even though the velocity - acceleration sign combination in the problem statement might be incorrect).

Final Answers (filling the blanks in order):

1. forward
2. backward
3. positive
4. negative
5. slowing down