Ask question

Ask question

All categories

1 year ago

10

Mr. Moore's physics class built different-shaped parachutes to see which shapes were more effective. The students tested the par

achutes by dropping them
from a height of 30 feet and timing the fall. They calculated the summary below:
The students wanted to see what happens to their times when they drop the parachutes from 45 feet. They find that every drop is increased by 2.5 seconds.
Find the new mean and standard deviation.
O Mean, 3.1 seconds; standard deviation, 0.6 second
O Mean, 5.6 seconds; standard deviation, 3.1 seconds
O Mean, 5.6 seconds; standard deviation, -1.9 seconds
O Mean, 8.1 seconds, standard deviation, 0.6 second

1 answer:

antoniya [11.8K]1 year ago

7 0

Your answer is the 5.6 seconds

You might be interested in

World wind energy generating1 capacity, W , was 371 gigawatts by the end of 2014 and has been increasing at a continuous rate of

Sunny_sXe [5.5K]

Answer:

a) $W(t) = 371(1.168)^{t}$

b) Wind capacity will pass 600 gigawatts during the year 2018

Step-by-step explanation:

The world wind energy generating capacity can be modeled by the following function

$W(t) = W(0)(1+r)^{t}$

In which W(t) is the wind energy generating capacity in t years after 2014, W(0) is the capacity in 2014 and r is the growth rate, as a decimal.

371 gigawatts by the end of 2014 and has been increasing at a continuous rate of approximately 16.8%.

This means that

$W(0) = 371, r = 0.168$

(a) Give a formula for W , in gigawatts, as a function of time, t , in years since the end of 2014 . W= gigawatts

$W(t) = W(0)(1+r)^{t}$

$W(t) = 371(1+0.168)^{t}$

$W(t) = 371(1.168)^{t}$

(b) When is wind capacity predicted to pass 600 gigawatts? Wind capacity will pass 600 gigawatts during the year?

This is t years after the end of 2014, in which t found when W(t) = 600. So

$W(t) = 371(1.168)^{t}$

$600 = 371(1.168)^{t}$

$(1.168)^{t} = \frac{600}{371}$

$(1.168)^{t} = 1.61725$

We have that:

$\log{a^{t}} = t\log{a}$

So we apply log to both sides of the equality

$\log{(1.168)^{t}} = \log{1.61725}$

$t\log{1.168} = 0.2088$

$0.0674t = 0.2088$

$t = \frac{0.2088}{0.0674}$

$t = 3.1$

It will happen 3.1 years after the end of 2014, so during the year of 2018.

7 0

1 year ago

If you know that a < b, and both a and b are positive numbers, then what must be true about the relationship between the oppo

Ymorist [56]

Answer:

The number further left on a number line is the smaller number. For positive numbers, the number closest to zero is smaller. For negative numbers, the number closest to zero is larger. If a is less than b, and they are both positive, then a is closer to 0 than b. The opposite of a is also closer to zero than the opposite of b, so the opposite of a must be larger than the opposite of b.

Step-by-step explanation:

6 0

2 years ago

Read 2 more answers

The following model can be used to study whether campaign expenditures affect election outcomes: voteA = β0 + β1log(expendA) + β

rosijanka [135]

Answer:

(i) It represents change in expenditure by candidates A; (ii) $H_0:\beta_1+\beta_2=0$

Step-by-step explanation:

6 0

1 year ago

Estimate the quotient 57.8 ÷81

natita [175]

An estimation of 0.7
though the actual answer is 0.713580247

8 0

2 years ago

Pierre lifts a 60-kg crate onto a truck bed 1 m high in 3 s. Marie lifts twenty-four 2.5-kg boxes onto the same truck bed in a t

lys-0071 [83]

Answer:

Pierre operates at a greater power level than Marie.

Marie and Pierre do the same amount of work

Step-by-step explanation:

Mass of crate=60kg

Height of truck bed=1 m

Time=3s

Pierre's work done= $60\times 1\times 9.8=588J$

Using formula Work done=mgh

Where m=mass of object

g=Acceleration due to gravity=9.8 $m/s^2$

Power= $\frac{w}{t}$

Using the formula

Pierre's power= $\frac{588}{3}=196watt$

Mass of box=2.5Kg

Total number of boxes=24

Total mass of boxes= $2.5\times 24=60kg$

Time=2 min= $2\times 60=120s$

1 min=60 s

Marie;s work done= $60\times 1\times 9.8=588J$

Marie's power= $\frac{588}{120}=4.9watt$

Pierre operates at a greater power level than Marie.

Marie and Pierre do the same amount of work

7 0

2 years ago