Answer:
- <u>0.5 s</u> (using 1 significan figure since the initial velocity is given with 1 significant figure)
Explanation:
Let's see what each term in the function v (t) = - 9.8t + 5 means:
The variable t is the time
The coffecient - 9.8 (which is negative) means that the velocity is reduced 9.8 m/s each second.
That means that the motion is uniformly decelerated with acceleration - 9.8 m/s².
The term + 5, means that the object was launched with an upward velocity of 5 m/s.
Hence the equation tells that after the object was launched upward it starts to lose speed and will reach a maximum height when the velocity is equal to zero, from which it starts falling.
So, you can calculate when the object reachs it maximum height and starts falling by making the velocity, v (t), equal to zero and solving for t. This is how you do it:
- v (t) = 0
- 0 = - 9.8t + 5
- 9.8t = 5 remember that the units of 9.8 is m/s² and of 5 is m/s
- t = 5 m/s / 9.8 m/s² = 0.51 s
So, the object starts fallin at 0.51 s. Since, the velocity is reported with 1 significant digit you answer should also show 1 significant digit, which means t = 0.5 s.
Answer:
48%
Step-by-step explanation:
I like to look at percentages as test grades. If you got a 130/250 on a test, you would simply need to view the dash line as a 'divided by'. So you would figure 130 divided by 250 is .52, or 52%... Then, you would need to subtract 52 from 100 to get 48% to get the percentage of people who do not walk to school.
<span>4/100×50 is your answer $2</span>
Answer: Choice C)
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mean = xbar = (2400+1750+1900+2500+2250+2100)/6
mean = 2150
Subtract the data values from the mean to get
2400-2150 = 250
1750-2150 = -400
1900-2150 = -250
2500-2150 = 350
2250-2150 = 100
2100-2150 = -50
The differences are: 250, -400, -250, 350, 100, -50
Then you square those values and add up the squares
(250)^2 + (-400)^2 + (-250)^2 + (350)^2 + (100)^2 + (-50)^2 = 420,000
Answer:
Step-by-step explanation:
radius of semicircle = 5
area of semicircle = πr² = 25π
area of rectangle = 10×14 = 140
total area = 140 + 25π ≅ 218.54 square units
