Answer:
30.46 kgm/s
Explanation:
According to conservation law of momentum, the magnitude of the impulse J that the ground gave the ball equals to the change in momentum of the ball before and after it hits the ground.
Before the hit, the ball velocity is 6m/s, so its momentum is 6 * 2.89 = 17.34 kgm/s
After the hit, the ball velocity is -4.54 m/s in the opposite direction, so its momentum is 2.89*(-4.54) = -13.12 kgm/s
So the change of momentum, and also the impulse is
17.34 - (-13.12) = 30.46 kgm/s
Answer: 15.87 m
From the equation of motion:
where, 
is the distance traveled, 
is the initial velocity, 
is the acceleration and 
is the time.
The rock free falls under gravity. Initial velocity, 
, 
It took 
for rock to hit the water.
Substitute the values in the given equation:
Hence, the water is 15.87 m below the top level of the well.
Option B The thickness of the central portion of a thin conveying lens can be determined very accurately by using a micrometer screw gauge.
<h3>What can be measured using a micrometer screw gauge?</h3>
One micrometer of thickness can be measured with a micron micrometre screw gauge. A Use of Micrometer Screw Gauge as like example Upon turning the screw of the micrometer screw gauge four times, a 2 mm space is covered.
<h3>What purposes does a micrometer serve?</h3>
A tool known as a micrometer is used to measure solid objects’ lengths, thicknesses, and other dimensions precisely and linearly.
<h3>What is the micrometer screw gauge’s SI unit?</h3>
The SI symbol m is also known as a micron, which is an SI-derived unit of length equaling 1106 meters, where 106 is the SI standard prefix for the prefix “micro-.” A micrometer is one-millionth of a meter.
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