How to find velocity

Would a Black T shirt or a White T shirt be hotter on a summer day?

tamaranim1 [39]

Answer:

a black T-shirt would be hotter

Explanation:

dark colors absorb heat. light colors reflect it.

7 0

3 years ago

Read 2 more answers

A circuit consists of a 6 ohm resistor, a 0.2 farad capacitor, and an AC voltage source supplying V(t) = 120 cos(20 t) volts. Wr

Zinaida [17]

Answer:

q = 24 cos (20t) (1- e (-t / 1.2))

Explanation:

To work this circuit we use the mesh equation (Kirchoff) that states that the voltage in a closed circuit is zero

Vg + Vr + Vc = 0

Where Vg is the generator voltage, Vr the resistance voltage and Vc the capacitor voltage

Vg = 120 cos 20t = V

Vr = i R

Vc = q / C

We see that in one term we have the current (i) and in another the load (q), but there is a relationship between the two

i = dq / dt

Let's replace in the initial equation

V + R dq / dt + q / C = 0

Reorder the terms

Rdq / dt + q / C - V = 0

dq / dt + q / rC - V / R = 0

dq / dt = V / r -q / RC

dq / (V / R -q / RC) = dt

we integrate

∫I dq / (V / R - 1 / RC q) = ∫ dt

We change variables

u = (V / R - 1 / RC q)

du = -1 / RC dq

∫ dq / (V / R - 1 / RC q) = -RC ∫ du / u

-RC ln u = -RC ln (V / R - 1 / RC q)

We evaluate between the limits of integration, the lower t = 0 q (0) = 0

-RC [ln (V / R - 1 / RC q) - ln (V / R)] = t

[ln (V / R - 1 / RC q) - ln (V / R)] = -t / RC

Ln (V / R - 1 / RC q) / (V / R)] = -t / RC

Ln (1 - 1 / VC q)) = (-t / RC)

Ln (VC- q) = ln (VC) (-t / RC)

VC-q = VC e (-t / RC)

q = VC - Vc e (-t / RC)

q = VC (1- e (-t / RC)

We substitute the values they give us

q = (120 cos (20t) 0.2) (1- e (-t / 6 0.2))

q = 24 cos (20t) (1- e (-t / 1.2))

7 0

4 years ago

A(n) _____ wave is a disturbance in matter that transfers

saul85 [17]

Thermal it’s the only answer that makes sense of course (:

3 0

4 years ago

A bouncy ball is being thrown upwards with a velocity of 34 meters per second if you caught the ball at the same height you rele

Serga [27]

It took the ball 6.94 seconds to make the trip

Explanation:

A bouncy ball is being thrown upwards with a velocity of 34 meters per

second and you caught the ball at the same height you released it

1. The initial velocity of the ball is 34 m/s upward

2. The acceleration of gravity is -9.8 m/s²

3. You caught the ball at the same height you released it

We need to find how long it takes the ball to make the trip

You caught the ball at the same height you released it, then

→ The displacement of the trip s = zero meter

→ The ball thrown upward with initial velocity u = 34 m/s

→ The acceleration of gravity g = -9.8 m/s²

→ s = u t + $\frac{1}{2}$ g t²

Substitute the values of u , g , s in the rules

→ 0 = 34 t + $\frac{1}{2}$ (-9.8) t²

→ 0 = 34 t - 4.9 t²

Multiply both sides by -1

→ 4.9 t² - 34 t = 0

Take t as common factor

→ t(4.9 t - 34) = 0

Equate each factor by 0

→ t = 0 ⇒ initial position

→ 4.9 t - 34 = 0

Add 34 to both sides

→ 4.9 t = 34

Divide both sides by 4.9

→ t = 6.94 seconds ⇒ final position

It took the ball 6.94 seconds to make the trip

Learn more:

You can learn more about free fall in brainly.com/question/5531630

#LearnwithBrainly

5 0

4 years ago

A particle in uniform circular motion requires a net force acting in what direction? Group of answer choices In the direction of

Annette [7]

Answer:

Towards the center of the circle

Explanation:

When an object is moving in uniform circular motion, it means that it is moving at a constant speed in a circular path.

In order to follows a circular path, the particle must have a net force acting on it, that it makes it constantly changing direction - and therefore, causing an acceleration - and this force is called centripetal force.

The direction of this centripetal force is always towards the centre of the circular path.

The nature of the centripetal force is always different, depending on the situation. For instance: for a satellite orbiting the Earth in circular motion, the centripetal force is provided by the force of gravity. For a car moving round a curve, the centripetal force is provided by the force of friction between the tyres and the road.

The magnitude of the centripetal force is given by

$F=m\frac{v^2}{r}$

where

m is the mass of the object

v is its speed

r is the radius of the circle

3 0

3 years ago