Newton's First Law Physics Example 4
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Example 4
mediumA bus travels at and brakes suddenly. A backpack on the floor slides forward. According to Newton's first law, what was the backpack's velocity immediately before friction acted on it?
Solution
- 1 Newton's first law says an object keeps its current velocity unless a net force changes it.
- 2 So immediately before friction acted, the backpack kept moving with the bus's original velocity of forward.
Answer
The backpack slides forward because inertia resists the change in motion. Braking slows the bus, but the backpack initially continues at the same velocity until friction exerts a force on it.
About Newton's First Law
An object at rest stays at rest, and an object in motion continues moving at constant velocity in a straight line, unless acted upon by.
Learn more about Newton's First Law →More Newton's First Law Examples
Example 1 easy
A book rests on a table. The weight of the book is [formula] downward. What is the normal force exer
Example 2 mediumA hockey puck slides across a frictionless ice surface at [formula]. What is the puck's velocity aft
Example 3 easyA car travels at a constant velocity of [formula] on a straight road. What is the net force acting o