All categories

3 years ago

Batteries are usually identified by their voltage.

Physics

1 answer:

Fynjy0 [20]3 years ago

7 0

Answer:

Explanation:

Given parameters:

Electrical energy = 18J

Quantity of charge Q = 12C

Unknown:

Voltage = ?

Solution:

The expression of electrical potential energy is given as:

Electrical potential energy = $\frac{1}{2}$ c v²

c is the quantity of charge

v is the voltage

18 = $\frac{1}{2}$ x 12 x v²

18 = 6v²

v² = 3

v = 1.7v

You might be interested in

An unmarked police car traveling a constant 38.6 m/s is passed by a speeder traveling 53.4 m/s. Precisely 2.2 seconds after the

Juliette [100K]

Answer:

The unmarked police car needs approximately 71.082 seconds to overtake the speeder.

Explanation:

Let suppose that speeder travels at constant velocity, whereas the unmarked police car accelerates at constant rate. In this case, we need to determine the instant when the police car overtakes the speeder. First, we construct a system of equations:

Unmarked police car

$s = s_{o}+v_{o,P}\cdot (t-t') + \frac{1}{2}\cdot a\cdot (t-t')^{2}$ (1)

Speeder

$s = s_{o} + v_{o,S}\cdot t$ (2)

Where:

$s_{o}$ - Initial position, measured in meters.

$s$ - Final position, measured in meters.

$v_{o,P}$ , $v_{o,S}$ - Initial velocities of the unmarked police car and the speeder, measured in meters per second.

$a$ - Acceleration of the unmarked police car, measured in meters per square second.

$t$ - Time, measured in seconds.

$t'$ - Initial instant for the unmarked police car, measured in seconds.

By equalizing (1) and (2), we expand and simplify the resulting expression:

$v_{o,P}\cdot (t-t')+\frac{1}{2}\cdot a\cdot (t-t')^{2} = v_{o,S}\cdot t$

$v_{o,P}\cdot t -v_{o,P}\cdot t' +\frac{1}{2}\cdot a\cdot t^{2}-a\cdot t'\cdot t+\frac{1}{2}\cdot a\cdot t'^{2} = v_{o,S}\cdot t$

$\frac{1}{2}\cdot a\cdot t^{2}+[(v_{o,P}-v_{o,S})-a\cdot t']\cdot t -\left(v_{o,P}\cdot t'-\frac{1}{2}\cdot a\cdot t'^{2}\right) = 0$

If we know that $a = 1.6\,\frac{m}{s^{2}}$ , $v_{o,P} = 0\,\frac{m}{s}$ , $v_{o,S} = 53.4\,\frac{m}{s}$ and $t' = 2.2\,s$ , then we solve the resulting second order polynomial:

$0.8\cdot t^{2}-56.92\cdot t +3.872 = 0$ (3)

$t_{1} \approx 71.082\,s$ , $t_{2}\approx 0.068$

Please notice that second root is due to error margin for approximations in coefficients. The required solution is the first root.

The unmarked police car needs approximately 71.082 seconds to overtake the speeder.

3 0

3 years ago

Name one property of each planet.

Archy [21]

Answer:

1)every planet move in elliptical path.

3 0

4 years ago

The battery charger for an mp3 player contains a step-down transformer with a turns ratio of 1:29, so that the voltage of 120 v

kifflom [539]

Transformer contains two coils: primary and secondary. They allow change of voltage to lower or higher value. In first case we have step-down and in second case we have step-up transformer.

Formula used for transformer is:
$\frac{ N_{1} }{N_{2} } = \frac{ V_{1} }{V_{2} }$

Where:
N1 = number of turns on primary coil
N2 = number of turns on secondary coil
V1 = voltage on primary coil
V2 = voltage on secondary coil

In a step-down transformer primary coil has more turns than secondary coil. So the ratio 1:29 means that for each turn on secondary coil we have 29 turns on primary coil.

We can solve the equation for V2:
${V_{2}}=\frac{ V_{1}{N_{2} } }{N_{1} } \\ {V_{2}}=\frac{ 120*{x } }{29x } \\ {V_{2}}=4.14V$

Secondary coil provides voltage of 4.14V.

8 0

4 years ago

A small boat is moving at a velocity of 3.35m/s when it is accelerated by a river current perpendicular to the initial direction

mr_godi [17]

Answer:

v =7.1 m/s

Explanation:

Given that

u = 3.35 m/s

t= 5 s

a= 0.75 m/s²

The final velocity = v

We know v = u +at

v=final velocity

u=initial velocity

Now by putting the values in the above equation

v = 3.35 + 0.75 x 5 m/s

v =7.1 m/s

Therefore the final velocity will be 7.1 m/s

7 0

3 years ago

A uniform ladder is 10 m long and weighs 400 n. it rests with its upper end against a frictionless vertical wall. its lower end

Nikolay [14]

<h3><u>Answer;</u></h3>

200 N

<h3><u>Solution;</u></h3>

Given ;

Weight = 400 N

Length of the ladder = 10 m

Using the equation;

Torque = d x F, where F is the perpendicular force and d is the distance

Calculating torque about the lower end,

Tweight = Twall

400N(5cos30) = F (10sin30)

F = 200 N

Therefore, the magnitude of force exerted on the peg by the ladder is 200 N

5 0

4 years ago