What is the answer to this question?

Ball drop with kinetic and potential energy

bagirrra123 [75]

Answer:

When the ball is dropped on the ground, the potential energy convert into kinetic energy. It had potential energy when it was held in the air waiting to be dropped, and It had kinetic energy when it was dropped because kinetic energy is when it's moving. when you drop it, your moving it.

Step-by-step explanation:

your welcome *bows*

7 0

3 years ago

If 60% of a number is 8, find 30% of that number.

podryga [215]

60/100 = 8/x

Multiply both sides by 100

60 = 800/x

Multiply both sides by x

60x = 800

Divide both sides by 60

x = 13.3333333333333

0.3 • x = answer

Answer = 4

6 0

2 years ago

Our faucet is broken, and a plumber has been called. The arrival time of the plumber is uniformly distributed between 1pm and 7p

Ymorist [56]

Answer:

$E(A+B) = E(A)+E(B)=4+0.5 =4.5 hours$

$Var(A+B)= Var(A)+Var(B)=3+0.25 hours^2=3.25 hours^2$

Step-by-step explanation:

Let A the random variable that represent "The arrival time of the plumber ". And we know that the distribution of A is given by:

$A\sim Uniform(1 ,7)$

And let B the random variable that represent "The time required to fix the broken faucet". And we know the distribution of B, given by:

$B\sim Exp(\lambda=\frac{1}{30 min})$

Supposing that the two times are independent, find the expected value and the variance of the time at which the plumber completes the project.

So we are interested on the expected value of A+B, like this

$E(A +B)$

Since the two random variables are assumed independent, then we have this

$E(A+B) = E(A)+E(B)$

So we can find the individual expected values for each distribution and then we can add it.

For ths uniform distribution the expected value is given by $E(X) =\frac{a+b}{2}$ where X is the random variable, and a,b represent the limits for the distribution. If we apply this for our case we got: