A car accelerates from rest to a velocity of 5 meters/second in 4 seconds. What is its average acceleration over this period of
2 answers:
Answer:
Its acceleration is 1.25 meters/second2 ( )
Explanation:
Acceleration is defined as the rate of change of velocity per unit time:
where
v is the final velocity
u is the initial velocity
t is the time taken
In this problem, the initial velocity of the car is zero: u=0. The final velocity is v=5 m/s, and the time taken is t=4 s, so the acceleration is
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Answer:
Explanation:
Static friction occurs when an object initially starts at rest. When the surfaces of the materials touch, the microscopic unevenness interlock greatest with each other, causing the most friction out of the three.
During sliding friction, an object is already moving or in motion. The microscopic surfaces still interlock, but because the object is in motion, it has a momentum. Therefore, the magnitude of sliding friction is less than that of static friction.
Rolling friction occurs when an object rolls across some surface. Rather than surfaces interlocking, rolling friction is caused by the constant distortion of surfaces. As it rolls, the surfaces of the object are constantly wrapping and changing. This distortion causes the rolling friction. However, it is much less in magnitude when compared to static or sliding friction.