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Elden [556K]
3 years ago
9

A stopwatch is used to measure how long it takes a sprinter to run 100 meters. this stopwatch measures time intervals to hundred

ths of seconds. using the stopwatch the timekeeper measures the sprinter’s time as 9.88 seconds. the timekeeper then writes down the sprinter’s time as 9.88 0.005 s ± . what is wrong with this?
Physics
1 answer:
melamori03 [73]3 years ago
4 0
First you need to know the smallest counting unit in this case. As this stopwatch measures time intervals to hundredths of a second, the uncertainty should be ± 0.01s (seconds) NOT ± 0.005s. Hence 0.01 is the smallest counting unit in this case. Hence the answer should be 9.88 <span>± 0.01s.

-i
</span>
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Assuming a 8 kilogram bowling ball moving at 2 m/s bounces off a spring at the same speed that had before bouncing what is the a
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a) 32 kg m/s

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p_i = m u = (8 kg)(2 m/s)=16 kg m/s

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p_{fB}=m v_b =(8 kg)(-2 m/s)=-16 kg m/s

The final momentum after the collision is the sum of the momenta of the ball and off the spring:

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p_i = p_f\\p_i = p_{fB}+p_{fS}\\p_{fS}=p_i -p_{fB}=16 kg m/s -(-16 kg m/s)=32 kg m/s


b) -32 kg m/s

The change in momentum of bowling ball is given by the difference between its final momentum and initial momentum:

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c) 64 N

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F=\frac{\Delta p}{\Delta t}=\frac{-32 kg m/s}{0.5 s}=-64 N

The negative sign simply means that the direction of the force is opposite to the initial direction of the ball.


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Answer:

The answer is below

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6 0
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Please help
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4 0
4 years ago
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