True Or False: people in the U.S. consume more liters of water than those in developing nations.

NEED THIS ANSWERED ASAP!!!! IN MIDDLE OF TEST RN HELP PLZ

Marina86 [1]

The correct answer for this question would be option A. When Barry is conducting an experiment and rolls a tennis ball down a ramp, the statement that best describes the motion of the tennis ball is that, i<span>t does not exhibit projectile motion and follows a straight path down the ramp. Hope this helps.</span>

3 0

3 years ago

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I just don't know how to do the question (a) and (b)

ozzi

Using the equation

$F=ma$

we can observe that you have to apply a non-zero net force to an object in order to make it accelerate. In fact, if the net force is zero you have

$0=ma \iff a=0$

Since we're assuming $n\neq 0$

Now, if the 12N force is applied, the object moves with a constant speed. A constant speed means no acceleration, since by definition the acceleration is a change in speed.

If this sounds counterintuitive to you (why I'm applying a force but I have to acceleration?) think of when we drive a car: even if you want to keep your speed constant, you still have to use the gas pedal, just enough so that the push of the motor balances exactly the road/wheels friction. If you give less gas, the friction becomes stronger, and the car slows down. If you give more gas, the motor push becomes stronger, and the car accelerates.

Back to your exercise: constant speed means to acceleration, so the net force must be zero. This implies that the friction force is exactly 12N.

If the force is increased to 18N, there will be a net force of 6N pushing the object, causing it to accelerate. Using again the same equation of before, and plugging the 3kg mass in the equation, we have

$F=ma \iff 6=3a \iff a=2$

So, the object moves with constant acceleration and initial speed of 10m/s for 0.2 seconds. It's final speed will be

$v = v_0+at = 10+2\cdot 0.2 = 10.4$

5 0

3 years ago

When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of

svetlana [45]

Answer: When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent? The inside of the balloon does not represent any part of our universe.

7 0

2 years ago

How can you make the potential energy as high as possible in a magnetic field between one electromagnet and one piece of iron?

harkovskaia [24]

In step 1, to increase the potential energy, the iron will move towards the electromagnet.

In step 2, to increase the potential energy, the iron will move towards the electromagnet.

<h3>Potential energy of a system of magnetic dipole</h3>

The potential energy of a system of dipole depends on the orientation of the dipole in the magnetic field.

$U = \mu B$

where;

$\mu$ is the dipole moment
B is the magnetic field

$B = \frac{\mu_0 I}{2\pi r}$

$U = \mu\times (\frac{\mu_0 I}{2\pi r} )$

Increase in the distance (r) reduces the potential energy. Thus, we can conclude the following;

In step 1, to increase the potential energy, the iron will move towards the electromagnet.
In step 2, when the iron is rotated 180, it will still maintain the original position, to increase the potential energy, the iron will move towards the electromagnet.

Learn more about potential energy in magnetic field here: brainly.com/question/14383738

7 0

1 year ago

IN WHAT CONDITION DO SOUND ECHO

DerKrebs [107]

Answer:

The conditions necessary for hearing the echo. The distance between the sound source and the reflecting surface must not be less than 17 metres where the time period between hearing the original sound and its echo should not be less than 0.1 of a second.

6 0

2 years ago