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4 years ago

The joule is an example of units of work. Which of the following is not a valid unit of work? ft-lb (kg-m2)/s2 inch-ton lb/s2

Physics

1 answer:

Dahasolnce [82]4 years ago

5 0

The "<em>lb/s² </em>" is not a valid unit of work.

Each of the others is (a unit of force) x (a unit of distance) which is pretty much the definition of work.

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Two parallel metal plates are at a distance of 8.00 m apart.The electric field between the plates is uniform directed towards th

dezoksy [38]

<h2>The K.E of the charge is 1.02 x 10⁻¹⁷ J</h2>

Explanation:

When the charge of 2e is placed in between the plates .

The force applied on this charge by plates is = q E

here q is the magnitude of charge = 2 e = 2 x 1.6 x 10⁻¹⁹ C

and E is the magnitude of electric field intensity

The work done = Force x displacement

Thus W = q E x S

here S is displacement

Therefore W = 2 x 1.6 x 10⁻¹⁹ x 4 x 8

= 1.02 x 10⁻¹⁷ J

This work will be converted into the kinetic energy of charge .

Thus K.E = 1.02 x 10⁻¹⁷ J

4 0

3 years ago

To see if your results are reasonable, you can compare the final velocity of the stone as it falls down unwinding the wire from

pentagon [3]

Answer:

The velocity of the stone is 2.57 m/s.

Explanation:

Given that

Height = 0.337 m

We need to calculate the velocity of the stone

Using equation of motion

$v^2-u^2=2gh$

Where, v = velocity of stone

u = initial velocity

g = acceleration due to gravity

h = height

Put the value into the formula

$v^2-0=2\times9.8\times 0.337$

$v=\sqrt{2\times9.8\times0.337}$

$v=2.57\ m/s$

Hence, The velocity of the stone is 2.57 m/s.

7 0

4 years ago

a fire woman dropped a person onto the safety net. right before the person hit the net he had a velocity of 11.2m/s and 1800j of

Ludmilka [50]

Answer: 28.699

Explanation:

KE=1/2(mv²)

1800=1/2m (125.44)

14.349=2m

m=28.699

5 0

3 years ago

Read 2 more answers

To drive a typical car at 40 mph on a level road for one hour requires about 3.2 × 107 J of energy. Suppose we tried to store th

tatiyna

Answer:

9000RPM

Explanation:

"Angular velocity" is directly related to kinetic energy, that is, the Kinetic energy equation would allow an approximation to the resolution investigated in the problem.

The equation for KE is given by:

$KE = \frac{1}{2} lw ^ 2$

Now, starting from there towards the <em>Angular equation of kinetic energy</em>, the moment of inertia (i) is used instead of mass (m), and angular velocity (w) instead of linear velocity (V)

That's how we get

$KE_{Angular} = \frac{1}{2} Iw^2$

calculating the inertia for a solid cylindrical disk, of

m = 400kg

r = 1.2 / 2 = 0.6m

$I_{disk} = \frac{1}{2} mr^2 = (0.5) (400) (0.6)^2 = 72 kgm^2$

We understand that the total kinetic energy is 3.2 * 10 ^ 7J, like this:

$3.2*10^7 = \frac{1}{2} Iw^2 = (0.5) (72) w^2 = 36w^2$ $w^2 = 3.2*10^7 / 36 = 0.0888*10^7 = 88.8*10^4$

$w = 9.43*10^2 = 943 rad / s$

Thus,

943 rad / s ≈ 9000 rpm

6 0

3 years ago

How will a current change if the voltage in a circuit is held constant while the resistance doubles? 1. it's impossible to predi

laila [671]

According to Ohm's Law:

$I = \frac{V}{R}$

Where: V = Voltage
I = Current
R = Resistance

As you can see here, you can say that Current is directly proportional to Voltage and indirectly proportional to Resistance. This means that as the voltage increases, current increases and as the resistance increases, current decreases.

So in your scenario, if the voltage remains the same, but the resistance is doubled, that means that the current will be halved. So the answer to your question is 2. the current will drop to half of its original value.

4 0

3 years ago