Can an object's velocity change direction when its acceleration is constant?
a) No this is not possible because it is always speeding up
b) No this is not possible because it is always speeding up or always slowing down, but it can never turn around
c) Yes it is possible and an example is a rock thrown straight up
d) Yes it is possible and a car that starts from rest, speeds up, slows to a stop and then backs up is an example
I believe the answer is c)
Yes, you are correct. The answer is c) Yes, it is possible, and an example is a rock thrown straight up.
To determine whether an object's velocity can change direction when its acceleration is constant, we need to understand the relationship between velocity, acceleration, and direction.
Velocity is a vector quantity that includes both magnitude (speed) and direction. Acceleration, on the other hand, refers to how quickly an object's velocity changes over time. If an object's acceleration is constant, it means that its velocity is changing at a constant rate.
Now, let's consider the options given:
a) No, this is not possible because it is always speeding up.
This option is incorrect because an object can change its direction even when its acceleration is constant.
b) No, this is not possible because it is always speeding up or always slowing down, but it can never turn around.
This option is also incorrect because an object can indeed change its direction when its acceleration is constant.
c) Yes, it is possible, and an example is a rock thrown straight up.
This option is partially correct. When a rock is thrown straight up, its acceleration due to gravity is constant, but its velocity changes direction when it reaches its highest point and begins to fall back down. Therefore, the rock's velocity changes direction while its acceleration remains constant.
d) Yes, it is possible, and a car that starts from rest, speeds up, slows to a stop, and then backs up is an example.
This option is also correct. When a car starts from rest, accelerates in one direction, and then comes to a stop, its acceleration is constant throughout. When it reverses its motion and starts moving in the opposite direction, the car's velocity changes direction while its acceleration remains constant.
Based on the explanations above, the correct answer is indeed c) Yes, it is possible, and an example is a rock thrown straight up.
Actually, the correct answer is d) Yes, it is possible and a car that starts from rest, speeds up, slows to a stop, and then backs up is an example.
When an object's acceleration is constant, its velocity can change direction. This is because acceleration describes the rate at which an object's velocity changes, not just its speed. So, even if the acceleration is constant, the object can still change direction.
For example, when a car starts from rest, its acceleration is in the forward direction, causing the car's velocity to increase. Once it reaches a certain speed, the acceleration becomes zero, and the car continues to move with constant velocity. Then, if the driver applies the brake, the acceleration becomes negative (opposite direction of the initial acceleration), causing the car to slow down and eventually stop. Finally, if the driver switches to reverse gear and applies the accelerator, the car's velocity starts decreasing in the opposite direction, and it begins to move backward.