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3 years ago

7

A motor does a total of 480 joules of work in 5.0 seconds to lift a 12-kilogram block to the top of a rampThe average power deve

loped by the motor is

1 answer:

Flauer [41]3 years ago

3 0

Answer:

there it is fella

we neglect the mass data

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Consider a car that travels between points A and B. The car's average speed can be greater than the magnitude of its average vel

ryzh [129]

Answer: A.True

Explanation: simply put the magnitude of the speed is a function of Distance while the magnitude of velocity is a function of Displacement. Displacement is the average Distance moved in different directions which will be smaller in magnitude compared to the Total Distance used the calculating the magnitude of speed.

4 0

3 years ago

when an apple falls towards the earth the earth moves up to meet the apple. Is it true? If yes, why is the earth motion not noti

timurjin [86]

Answer:

Explanation:

The apple also exerts an equal and opposite force on the earth but earth does not move because the mass of apple is very small,due to which the gravitational force produces a large acceleration in it (a=F/m) and we can see the apple falling towards the earth but the mass of earth is very large,the same gravitational .

3 0

2 years ago

Is there a link between the number of bulbs and current drawn from the power pack?

LuckyWell [14K]

Answer:

Yes there is if number of bulb is high the bulbs wouldn't glow much brighter

Explanation:

5 0

2 years ago

the kinetic energy of an object of mass in moving with a velocity of 5 MS -1 is 25j what will be its kinetic energy when its vel

MAXImum [283]

Answer:

<em>When the speed is doubled, K = 100 J, when the speed is tripled, K = 225 J</em>

Explanation:

<u>Kinetic Energy </u>

Is the type of energy an object has due to its speed. It's proportional to the square of the speed.

The equation for the kinetic energy is:

$\displaystyle K=\frac{1}{2}mv^2$

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

The object has a kinetic energy of K=25 J when moving at v=5 m/s, thus the mass can be calculated by solving for m:

$\displaystyle m=\frac{2K}{v^2}$

$\displaystyle m=\frac{2*25}{5^2}=2$

m = 2 Kg

If the speed is doubled, v=10 m/s, the new kinetic energy is:

$\displaystyle K=\frac{1}{2}2\cdot 10^2$

K = 100 J

If the speed is tripled, v=15 m/s, the new kinetic energy is:

$\displaystyle K=\frac{1}{2}2\cdot 15^2$

K = 225 J

When the speed is doubled, K = 100 J, when the speed is tripled, K = 225 J

3 0

2 years ago

A battery is used to charge a parallel-plate capacitor, after which it is disconnected. Then the plates are pulled apart to twic

Igoryamba

Answer: C.

Explanation:

For a parallel-plate capacitor where the distance between the plates is d.

The capacitance is:

C = e*A/d

You can see that the distance is in the denominator, then if we double the distance, the capacitance halves.

Now, the stored energy can be written as:

E = (1/2)*Q^2/C

Now you can see that in this case, the capacitance is in the denominator, then we can rewrite this as:

E = (1/2)*Q^2*d/(e*A)

e is a constant, A is the area of the plates, that is also constant, and Q is the charge, that can not change because the capacitor is disconnected.

Then we can define:

K = (1/2)*Q^2/(e*A)

And now we can write the energy as:

E = K*d

Then the energy is proportional to the distance between the plates, this means that if we double the distance, we also double the energy.

8 0

2 years ago