PLESSSS HELP THIS IS FOR A TEST GRADE AND I NEVER LISTEN

1) A capacitor consists of two metal surfaces separated by an electrical insulator with no electrically conductive path through

ki77a [65]

Answer:

Current flows in a resistor-capacitor circuit because of the varying electric field across the plates of a capacitor induced by an AC voltage source (displacement current)

Explanation:

In a capacitor, current does not flow the same way it does in a circuit, that is through conduction. This is because there is a highly resistive material in between the plates of the capacitor. Rather current flows through a phenomenon called displacement current.

Because of change in charge accumulation with time above the plates, the electric field changes causing the displacement current.

Displacement current arises due to the flow of electrons as a result of the varying magnetic fields set up on the plates of the capacitor when supplied with an AC voltage. It is important to note that a DC voltage does not induce any displacement current.

Through this, phenomenon discovered by Maxwell, current is able to flow in a resistor-capacitor circuit despite the absence of an electrically conductive path through the plates.

7 0

3 years ago

A ball is thrown with a speed of 20 m/s at an angle of 40o above the horizontal from the top of a 22-m tall building.

MrRissso [65]

Answer:

(a). The distance is 49.79 m.

(b). The speed of the ball is 24.39 m/s.

Explanation:

Given that,

Speed = 20 m/s

Angle = 40°

Height = 22 m

Time = 3.25 sec

(a). We need to calculate the distance

Using formula of distance

$d=u\cos\theta\times t$

Put the value into the formula

$d=20\cos40\times3.25$

$d=49.79\ m$

(b). We need to calculate the horizontal velocity

Using formula of velocity

$v_{x}=u\cos\theta$

Put the value into the formula

$v_{x}=20\times\cos40$

$v_{x}=15.3\ m/s$

We need to calculate the vertical velocity

Using equation of motion

$v_{y}=u\sin\theta-gt$

Put the value into the formula

$v_{y}=20\sin40-9.8\times3.25$

$v_{y}=-19\ m/s$

Negative sign shows the opposite direction.

We need to calculate the speed of ball

Using formula of speed

$v=\sqrt{v_{x}^2+v_{y}^2}$

$v=\sqrt{(15.3)^2+(19)^2}$

$v=24.39\ m/s$

Hence, (a). The distance is 49.79 m.

(b). The speed of the ball is 24.39 m/s.

4 0

3 years ago

When water change into ice it contracts or expand plz answer fast..

mihalych1998 [28]

Answer:Yes, water indeed expands when it changes form from liquid to solid. And this is because water has a property called “hydrogen bonds”, and these bonds occur between each water molecule. But when water is in a liquid form these hydrogen bonds break more easily and occur less frequently. When the temperature drops the kinetic energy also drops, which in turn makes hydrogen bonds form more frequently. So the water molecules form a lattice, which is less dense than regular liquid water.

Explanation:

4 0

3 years ago

Read 2 more answers

A man stands on a platform that is rotating at 3.8 rpm; his arms are outstretched and he holds a brick in each hand. The rotatio

Ierofanga [76]

Answer:

a) 5.197rev/s

b) Kf/Ki =2.28

Explanation:

a) Angular momentum of the system L = Iw

ButLi=Lf

Kiwi =Ifwf

wf = (Ii/If)will = (4.65/3.4)×3.8=5.197rev/s

b)Kinetic energy KE= 0.5Iw^2

Ki = 0.5Iiwi^2

Kf=0.5Ifwf^2

Kf/Ki = Ifwf/Iiwi

Kf/Ki = (4.65/3.4))(5.197/3.8)

Kf/Ki = 1.22(1.368)^2

Kf/Ki = 2.28

8 0

3 years ago

Read 2 more answers

If the ankylosaurs starts running and accelerates at 1.3m/s^2 for 3 seconds how far does he make it before the velociraptor catc

sveta [45]

Acceleration is the change of velocity, and velocity is the change of distance. The opposite of finding change, or differentiation, is integration.

Acceleration = 1.3 m/s²

Velocity: ∫ 1.3 dx = 1.3x + c m/s

Distance: ∫ 1.3x dx = 1.3x²/2 + c m

Distance run: 1.3*3²/2 = 5.85 m

What bad thing happened?

7 0

3 years ago