______________ controls the flow of electric current. Answer!!! Please

Physics part 1 I need help answering these

alex41 [277]

Answer:

lhchccyohchocohchocoyxtidts8ts58d85dtitxicyi

6 0

3 years ago

There is a 247–m–high cliff at Half Dome in Yosemite National Park in California. Suppose a boulder breaks loose from the top of

Cerrena [4.2K]

Answer:

Vf = 69.61 m/s

Explanation:

We will use the third equation of motion to solve this problem:

$2gh = V_{f}^2 - V_{i}^2\\$

where,

g = acceleration due to gravity = 9.81 m/s²

h = height of cliff = 247 m

Vf = final velocity = ?

Vi = initial velocity = 0 m/s (boulder breaks loose from rest)

Therefore,

$(2)(9.81\ m/s^2)(247\ m) = V_{f}^2 - (0\ m/s)^2\\V_{f} = \sqrt{4846.14\ m^2/s^2}\\$

Vf = 69.61 m/s

8 0

3 years ago

Two parallel plates 19 cm on a side are given equal and opposite charges of magnitude 2.0 ✕ 10^−9 C. The plates are 1.8 mm apart

Romashka [77]

Answer:

E = 5291.00 N/C

Explanation:

Expression for capacitance is

$C = \frac{\epsilon A}{d}$

where

A is area of square plate

D = DISTANCE BETWEEN THE PLATE

$C = \frac{\epsilon\times(19\times 10^{-2})^2}{1.5\times 10^{-3}}$

$C = 24.06 \epsilon$

$C = 24.06\times 8.854\times 10^{-12} F$

$C =2.1\times 10^{-10} F$

We know that capacitrnce and charge is related as

$V = \frac{Q}{C}$

$= \frac{2\tiimes 10^{-9}}{2.\times 10^{-10}}$

v = 9.523 V

Electric field is given as

$E = \frac{V}{d}$

= $\frac{9.52}{1.8*10^{-3}}$

E = 5291.00 V/m

E = 5291.00 N/C

5 0

3 years ago

The radioactive element polonium decays according to the law given below where Q0 is the initial amount and the time t is measur

kogti [31]

Answer:

1280 mg

Explanation:

Radioactive decay is a phenomenon that occurs when a certain isotope of an element, said to be radioactive, decays, turning into a lighter nucleus and emitting radiation + energy in the process.

The radioactive decay of this isotope of polonium is described by the equation

$Q(t)=Q_0 2^{-\frac{t}{140}}$

where

$Q(t)$ is the amount of polonium left after time t

$Q_0$ is the amount of polonium t time t = 0

$140$ is the half-life of the polonium, in days (it is the time it takes for the initial element to halve its amount)

IN this problem, we know that:

After t = 560 days, the amount of polonium left is $Q(t)=80 mg$ . Therefore, we can re-arrange the equation, substituting t = 560 d, and solve for $Q_0$ to find the initial amount of polonium:

$Q_0 = Q(t) \cdot 2^{\frac{t}{140}}=(80)\cdot 2^{\frac{560}{140}}=1280 mg$

5 0

4 years ago

Testing Plant Growth with Fertilizer

kykrilka [37]

b) by the end of the fifth day, group b will be more than one cm taller than group a. eliminate

Explanation:

The correct prediction based on the data shown is that by the end of the fifth day, group B plants will be more than 1cm taller than group A plants.

let us examine the table closely;

Day Group A (Water Only) Plant Height (cm) Group B (Water and Fertilizer)

1 2.0 2.0

2 2.2 2.3

3 2.3 2.8

4 2.5 3.2

5 2.6 3.8

We can see that by the end of the fifth day, the height differences between the two plants, 3.8 - 2.6 = 1.2cm, this is greater than 1cm. This claim from the experiment is very correct.

Other predictions are false.

learn more:

Experiment brainly.com/question/5096428

#learnwithBrainly

5 0

3 years ago