Which of the following planets orbits the fastest around the sun?

Jorge hits a drum as hard as he can, and it makes a loud sound. Then he hits the same drum with less strength, and it makes a qu

Leviafan [203]

Answer:

when he uses more force to hit the drum then its makes a louder sound so the more force you hit the drum with then the louder it is.

8 0

3 years ago

Charge g is distributed in a spherically symmetric ball of radius a. (a) Evaluate the average volume charge density p. (b) Now a

nasty-shy [4]

Answer:

Explanation:

The volume of a sphere is:

V = 4/3 * π * a^3

The volume charge density would then be:

p = Q/V

p = 3*Q/(4 * π * a^3)

If the charge density depends on the radius:

p = f(r) = k * r

I integrate the charge density in spherical coordinates. The charge density integrated in the whole volume is equal to total charge.

$Q = \int\limits^{2*\pi}_0\int\limits^\pi_0 \int\limits^r_0 {k * r} \, dr * r*d\theta* r*d\phi$

$Q = k *\int\limits^{2*\pi}_0\int\limits^\pi_0 \int\limits^r_0 {r^3} \, dr * d\theta* d\phi$

$Q = k *\int\limits^{2*\pi}_0\int\limits^\pi_0 {\frac{r^4}{4}} \, d\theta* d\phi$

$Q = k *\int\limits^{2*\pi}_0 {\frac{\pi r^4}{4}} \, d\phi$

$Q = \frac{\pi^2 r^4}{2}}$

Since p = k*r

Q = p*π^2*r^3 / 2

Then:

p(r) = 2*Q / (π^2*r^3)

3 0

2 years ago

Two trains A and B of length 400 m each are moving on two parallel tracks with

Vinvika [58]

Answer:

The initial distance between the trains is 1450 m. 

Explanation:

In the question two trains are of equal length 400 m and moves at a uniform speed of 72 km/h. train A is moving ahead of train B. If the train B has to overtake train A it should accelerate.

Train B’s acceleration is $1m/s^2$ and it accelerated for 50 seconds.

 $a=1 m/s^2$ 

t=50 s 

initial speed u=72km/h 

we have to convert this speed into m/s 

 $u=72 \times 5/18=20 m/s$ 

Distance covered in accelerating phase $S=ut+1/2 at^2$ 

 $=20 \times 50+1/2 \times 1 \times 50^2$ 

 $=1000+1250=2250 m$ 

If a train is just behind another, the distance covered by the train located behind during overtaking phase will be equal to the sum of the lengths of the trains.

Here length of train A+length of train $B=400+400=800 m$ 

Hence the initial distance between the trains = $2250-800=1450 m$ 

6 0

3 years ago

Identify the situations that have an unbalanced force. Check all that apply. A baseball speeds up as it falls through the air. A

viktelen [127]

A baseball speeds up as it falls through the air.
Yes. Forces on the balloon are unbalanced.
The balloon is speeding up, so we know that the downward force
of gravity is stronger than the upward force of air resistance.

A soccer ball is at rest on the ground.
No. The ball is not accelerating, so we know that the forces on it
are balanced.
The downward force of gravity on the ball and the upward force
of the ground are equal.

An ice skater glides in a straight line at a constant speed.
No. The skater's speed and direction are not changing, so he is not
accelerating. That tells us that the forces on him are balanced.

A bumper car hit by another car moves off at an angle.
Yes. The direction in which the car was moving changed.
That's acceleration, so we know that the forces on it are unbalanced,
at least at the moment of impact.

A balloon flies across the room when the air is released.
Yes. The balloon was not moving. But when the little nozzle was
opened, it started to zip around the room. So its speed changed.
And, as it goes bloozing around the room, its direction keeps changing too.
There's a whole lot of acceleration going on, so we know the forces on it
are unbalanced.

5 0

3 years ago

Read 2 more answers

Jill leaves home and rides a distance of 70 km. It took her 2.5 hours. What is her speed?

Paraphin [41]

The answer is ...
28 km per hour

5 0

3 years ago