A disease that affects the skill is called

A book is sliding along a desk top. Because the book is in motion ,you know that the forces acting on the book are A. Balanced B

Virty [35]

Just because the book is moving doesn't tell you anything about the forces on it, or even whether there ARE any.

Just look at Newton's first law of motion, and this time, let's try and THINK about it too. It says something to the effect that any object continues in constant, uniform MOTION ..... UNLESS acted on by an external force.

4 0

4 years ago

At a rock concert, the sound intensity 1.0 m in front of the bank of loudspeakers is 0.10 W/m². A fan is 30 m from the loudspeak

Klio2033 [76]

To solve this problem we will apply the concepts related to the Area, the power and the proportionality relationships between intensity and distance.

The expression for sound power is,

$P = AI$

Here,

A = Area

I = Intensity

P = Power

At the same time the area can be written as,

$A = \frac{\pi d^2}{4}$

Now the intensity is inversely proportional to the square of the distance from the source, then

$I \propto \frac{1}{r^2}$

The expression for the intensity at different distance is

$\frac{I_1}{I_2}= \frac{r^2_2}{r_1^2}$

Here,

$I_1$ = Intensity at distance 1

$I_2$ = Intensity at distance 2

$r_1$ = Distance 1 from light source

$r_2$ = Distance 2 from the light source

If we rearrange the expression to find the intensity at second position we have,

$I_2 = I_1 (\frac{r_1^2}{r_2^2})$

If we replace with our values at this equation we have,

$I_2 = (0.10W/m^2)(\frac{1.0m^2}{30.0m^2})$

$I_2 = 1.11*10^{-4} W/m^2$

Now using the equation to find the area we have that

$A = \frac{\pi (8.4*10^{-3}m)^2}{4}$

$A = 5.5*10^{-5}m^2$

Finally with the intensity and the area we can find the sound power, which is

$P = AI$

$P = (5.5*10^{-5}m^2)(1.11*10^{-4}W/m^2)$

$P = 6.1*10^{-9}J/s$

Power is defined as the quantity of Energy per second, then

$E = 6.1*10^{-9}J$

8 0

4 years ago

According to the table what was the hikers total displacement the graph has 4km 6km 4km 6km

Xelga [282]

Answer:

0

Explanation:

0 is the answer

6 0

3 years ago

7. Katie and her best friend Liam play tennis every Saturday morning. When Katie serves the ball to Liam, it

KIM [24]

a. 4.52 m/s south

Velocity is a vector, whose magnitude is defined as the ratio between the displacement of the object and the time taken for the displacement to occur:

$v=\frac{d}{t}$

where

d is the displacement

t is the time

Velocity is a vector, so it also has a direction, which corresponds to that of the displacement.

For the ball in this problem,

d = 9.5 m south

t = 2.1 s

Substituting, we find:

$v=\frac{9.5}{2.1}=4.52 m/s$

and the directiion is the same as the displacement (south).

b. 4.52 m/s north

For this part, we must keep in mind that the speed is the magnitude of the velocity; however, speed is a scalar, so it does not have a direction.

Here we are told that the tennis ball travels at constant speed, so on its way back from Liam to Katie the ball's velocity is still the same as before, therefore

$|v| = 4.52 m/s$

However, this time the direction is opposite to before, since the ball is travelling in the opposite direction.

Therefore, the ball's velocity when Liam returns Katie's service is

4.52 m/s north

8 0

3 years ago

Countercurrent exchange is evident in the flow of _____.

Anna35 [415]

Answer:

In the water flow mechanism in fishes when they take in oxygen using the gills

Explanation:

Fish gills are organ that facilites respiration under water,its Mechanism is described below,first water is pulled in the mouth of the fish and pumped over the gills,while the blood flow in opposite direction known as counter current exchange helps in pushing low oxgen water away and retaining high oxgen in the fish blood.

4 0

3 years ago