<span>The wheel accelerates uniformly for 10s and reaches the operating angular velocity of 58 rad/s. The wheel is run at that angular velocity for 21s and then power is shut off. The wheel slows down at 2.4rad/s^2 until it stops. </span>
There are five key factors involved when cleaning that are equally important: time, temperature, mechanical action, chemical reaction and procedures. Balancing these factors will produce the best possible results.
<h3>
Answer:</h3>
60 days
<h3>
Explanation:</h3>
Half-life is the amount of time it takes half of a substance to decay away.
Guess and Check
One method for solving half-life problems like this is to guess and check. To do this, we can continue to divide 475mg by 2 until we get to 30mg.
- 475 ÷ 2 = 237.5
- 237.5 ÷ 2 = 118.75
- 118.75 ÷ 2 = 59.375
- 59.375 ÷ 2 = 29.6875
As seen here, it takes approximately 4 half-lives for this sample of Ra-225 to decay to 30mg. Now, we can multiply 4 by the length of the half-life, 15 days.
Fractions
Another way to solve this is to use fractions.
- 16 is equivalent to
.
This means that it takes 4 half-lives for 475mg to decay to 30mg. Using the same method above, we can tell that 4 half-lives are 60 days.
Important Note
In this question, I rounded occasionally. So, not all of the values are exact, but they are all very close.
The additional measurements which must be made to determine the momentum of block 2 after the collision is both the mass and the post-collision speed of block 1
<h3>What is momentum?</h3>
Momentum can be defined as a scalar quantity that involves the multiplication of the mass of an object by its velocity.
In Physics, the momentum of an object such as a block, is calculated by using this formula;
Momentum = mass × velocity
In conclusion, we can deduce that the additional measurements which must be made to determine the momentum of block 2 after the collision is both the mass and the post-collision speed of block 1.
Read more on momentum here: brainly.com/question/15517471
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