Which would take more force to stop in 10 seconds: an 8.0-kilogram ball rolling in a straight line at a speed of 0.2 m/sec or a
1 answer:
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Answer:
Look to the explanation
Explanation:
<u><em>Average velocity:</em></u> is the average rate of change of displacement with
respect to time
Average velocity is a measure for distance traveled in a given time
We can calculate the average velocity by the rule
where s is the displacement and t is the time
<u><em>Instantaneous velocity:</em></u> is the velocity of an object in motion at a
specific point (x , t)
instantaneous velocity is the limit of velocity as the change in time
approaches zero
We can calculate the instantaneous velocity by the rule
<u>Average velocity</u> is <u>equal</u> to the <u>instantaneous velocity</u> when
<u>acceleration</u> is <u>zero</u>
Answer:
400 years
Explanation:
The equation that describes the decay of a radioactive sample is:
(1)
where
m(t) is the amount of sample left at time t
is the initial amount of the sample
is the half-life, which is the time taken for the sample to halve
In this problem we have:
is the half-life of Nickel-63
After a time t, the amount of sample left is 6.25% of the original one, which means that
So we can rewrite the equation (1) and solving for t to find the time:
Answer:
The graph is shown below.
The athlete's speed at the finish line is 11 m/s
Total distance covered is 82.5 m.
Explanation:
The graph of speed versus time is drawn below.
Acceleration in the first 5 seconds, m/s²
From the graph, the slope of line OA is the acceleration in the first 5 seconds.
Slope of line OA is given as:
Now, the length AD is nothing but speed at point A or B as AB is a straight line.
Therefore, the speed when crossing the finish line is the speed at B which is equal to 11 m/s.
Distance covered is given by the total area under the graph.
The total area can be divided into two shapes; a triangle and a rectangle.
The area under the graph is the sum of areas of triangle OAD and rectangle ABCD.
Area of triangle OAD is,
Area of rectangle ABCD is,
Therefore, the total distance covered till the finish line is given as:
