it took a toy car 1 minute to roll 180 ft. what was this cars average rate of speed, in ft per second?

A 300-N force acts on a 25-kg object. the acceleration of the object is ___.

atroni [7]

The answer for that question is 12 m/s2. Your multiplying 25x12 which equals 300.

3 0

3 years ago

Troy and Lisa were shopping for school supplies. Each purchased different quantities of the same notebook and thumb drive. Troy

MaRussiya [10]

Answer:

The cost of each notebook is $3 and the cost of each thumb drive is $14.

Step-by-step explanation:

In order to solve this question we will attribute variables to the notebook and thumb drive. The price of a notebook we will call "x" and the price of a thumb drive will be "y". We now can create equations that represents the total amount spent by each person on these items. To do that we need to take the amount of each item that was bought and multiply it by it's price.

For Troy:

4*x + 6*y = 96

For Lisa:

2*x + 4*y = 62

We now have a system of equations and we can solve them by isolate one of he variables in one of the equations and using that value on the other. Using the second equation we have:

2*x + 4*y = 62

4*y = 62 - 2*x

y = 15.5 - 0.5*x

Using this expression on the first equation:

4*x + 6*(15.5 - 0.5*x) = 96

4*x + 93 - 3*x = 96

x = 96 - 93 = 3

We can now find the value of y:

y = 15.5 - 0.5*(3) = 14

The cost of each notebook is $3 and the cost of each thumb drive is $14.

7 0

3 years ago

Please anyones good in math 13 a/b/c/d

inessss [21]

Answer:

$\frac{7}{15}$

Step-by-step explanation:

4/5*3/3-1/3

4/5*3/3-1/3*5/5

4*3/15-5/15

4*3-5/15

12-5/15

7/15

3 0

3 years ago

What is the formula for the expected number of successes in a binomial experiment with n trials and probability of success p? C

charle [14.2K]

Answer:

$(D)E[ X ] =np.$

Step-by-step explanation:

Given a binomial experiment with n trials and probability of success p,

$f(x)=\left(\begin{array}{c}n\\k\end{array}\right)p^x(1-p)^{n-x}, 0\leq x\leq n$

$E(X)=\sum_{x=0}^{n}xf(x)= \sum_{x=0}^{n}x\left(\begin{array}{c}n\\k\end{array}\right)p^x(1-p)^{n-x}$

Since each term of the summation is multiplied by x, the value of the term corresponding to x = 0 will be 0. Therefore the expected value becomes:

$E(X)=\sum_{x=1}^{n}x\left(\begin{array}{c}n\\x\end{array}\right)p^x(1-p)^{n-x}$

Now,

$x\left(\begin{array}{c}n\\x\end{array}\right)= \frac{xn!}{x!(n-x)!}=\frac{n!}{(x-)!(n-x)!}=\frac{n(n-1)!}{(x-1)!((n-1)-(x-1))!}=n\left(\begin{array}{c}n-1\\x-1\end{array}\right)$

Substituting,

$E(X)=\sum_{x=1}^{n}n\left(\begin{array}{c}n-1\\x-1\end{array}\right)p^x(1-p)^{n-x}$

Factoring out the n and one p from the above expression:

$E(X)=np\sum_{x=1}^{n}n\left(\begin{array}{c}n-1\\x-1\end{array}\right)p^{x-1}(1-p)^{(n-1)-(x-1)}$

Representing k=x-1 in the above gives us:

$E(X)=np\sum_{k=0}^{n}n\left(\begin{array}{c}n-1\\k\end{array}\right)p^{k}(1-p)^{(n-1)-k}$

This can then be written by the Binomial Formula as:

$E[ X ] = (np) (p +(1 - p))^{n -1 }= np.$

5 0

3 years ago

IVE BEEN STUCK ON THIS FOR ABOUT 3 HOURS

V125BC [204]

A. Is the attached image. The slope is 7.5x

b. 1 = 7.5x

x = 1.33333…

This is hours so we must multiply this by 60

x = 8 min

3 0

2 years ago