Question

So, please check my answers here:

1. Which example identifies a change in motion that produces acceleration?
A) A speed skater moving at a constant speed on a straight track**
B) A ball moving at constant speed around a circular track
C) A particle moving in a vacuum at constant velocity
D) A vehicle moving down the street at a steady speed

2. Objects in free fall near the surface of Earth experience
A) Constant speed
B) Constant velocity
C) Constant acceleration**
D) Constant distance

3. Suppose you increase your walking speed from 1 m/s to 3 m/s in a period of 1 s. What is your acceleration?
A) 2 m/s^2
B) 5 m/s^2
C) 4 m/s^2
D) 3 m/s^2**

4. The slope of a speed-time graph indicates
A) Direction
B) Acceleration**
C) Velocity
D) Speed

5. A train approaching a crossing changes speed from 25 m/s to 10 m/s in 240 s. How can the train's acceleration be described?
A) The train's acceleration is positive
B) The train is not accelerating
C) The train will come to rest in 6 minutes
D) The train's acceleration is negative**

6. What is a good definition of acceleration?
A) How fast a speed is changing at a specific instant**
B) How fast a velocity is changing at a specific instant
C) How fast a direction is changing at a specific instant
D) Each of the above

Are my answers correct? If not, let me know which ones aren't and I'll fix them. (✿◠‿◠)

Answer 1

Half are wrong. 1,3,6

Answer 2

answers?