According to our principle, when an object is slowing down, the acceleration is in the opposite direction as the velocity. Thus, this object has a negative acceleration.An object with negative acceleration could be speeding up, and an object with positive acceleration could be slowing down.
Answer:
Explanation:
To listen the sound, the air particles must vibrates.
As the sound energy produce vibrations in the medium, so the air column exerts pressure, and then the air molecules set into vibrations and we hear sound as the diaphram set into vibrations.
<span> 4. 1 and 2 only.
1. the downward force is the force of gravity.
2. The upward force exerted is the Normal reaction from the floor.
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Newton #2: F = M a
(1 x 10³ kg) (4.5 m/s²) = 4,500 newtons
