Which of the following is not a possible environmental consequence of urban sprawl?

A circular coil of wire having a diameter of 20.0 cm and 3000 turns is placed in the earth's magnetic field with the normal of t

Bess [88]

Explanation :

It is given that,

Diameter of the coil, d = 20 cm = 0.2 m

Radius of the coil, r = 0.1 m

Number of turns, N = 3000

Induced EMF, $\epsilon=1.5\ V$

Magnitude of Earth's field, $B=10^{-4}\ T$

We need to find the angular frequency with which it is rotated. The induced emf due to rotation is given by :

$\epsilon=NBA\omega$

$\omega=\dfrac{\epsilon}{NBA}$

$\omega=\dfrac{1.5}{3000\times 10^{-4}\times \pi (0.1)^2}$

$\omega=159.15\ rad/s$

So, the angular frequency with which the loop is rotated is 159.15 rad/s. Hence, this is the required solution.

3 0

2 years ago

A woman walked 115 m. As she did so, her speed increased from 4.20 m/s to 5.00 m/s. How long did it take her to walk this distan

ASHA 777 [7]

Answer:

25 seconds

Explanation:

Assuming the woman is accelerating at a constant rate of $a \;\;m/s^2$ from the initial velocity, u=4.20 m/s, to the final velocity, v=5.00 m/s.

Let she takes t seconds to cover the distance, s=115 m.

As acceleration, $a=\frac{v-u}{t}=\frac{5-4.2}{t}$

$\Rightarrow at=0.8\cdots(i)$

Now, from the equation of motion

$s=ut+\frac 12 at^2$

$\Rightarrow s=ut+\frac 12 at(t)$

$\Rightarrow 115=4.2t+\frac 12 \times 0.8 t$ [ from equation (i)]

$\Rightarrow 115=(4.2+0.4)t$

$\Rightarrow t= 115/4.6 = 25$ seconds.

Hence, she takes 25 seconds to walk the distance.

5 0

3 years ago

How are electromagnetic waves different from all other waves

Verdich [7]

Answer:

Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.

Explanation:

6 0

3 years ago

Two forces are going in opposite directions each force is 9.

professor190 [17]

Answer:

The net force is zero.

Explanation:

Two opposing and equal forces cancel each other out, giving you a net force of zero.

7 0

3 years ago

A loaded ore car has a mass of 950 kg. and rolls on rails ofnegligible friction. It starts from rest ans is pulled up a mineshaf

stiks02 [169]

(a) 10241 W

In this situation, the car is moving at constant speed: this means that its acceleration along the direction parallel to the slope is zero, and so the net force along this direction is also zero.

The equation of the forces along the parallel direction is:

$F - mg sin \theta = 0$

where

F is the force applied to pull the car

m = 950 kg is the mass of the car

$g=9.8 m/s^2$ is the acceleration of gravity

$\theta=30.0^{\circ}$ is the angle of the incline

Solving for F,

$F=mg sin \theta = (950)(9.8)(sin 30.0^{\circ})=4655 N$

Now we know that the car is moving at constant velocity of

v = 2.20 m/s

So we can find the power done by the motor during the constant speed phase as

$P=Fv = (4655)(2.20)=10241 W$

(b) 10624 W

The maximum power is provided during the phase of acceleration, because during this phase the force applied is maximum. The acceleration of the car can be found with the equation

$v=u+at$

where

v = 2.20 m/s is the final velocity

a is the acceleration

u = 0 is the initial velocity

t = 12.0 s is the time

Solving for a,

$a=\frac{v-u}{t}=\frac{2.20-0}{12.0}=0.183 m/s^2$

So now the equation of the forces along the direction parallel to the incline is

$F - mg sin \theta = ma$

And solving for F, we find the maximum force applied by the motor:

$F=ma+mgsin \theta =(950)(0.183)+(950)(9.8)(sin 30^{\circ})=4829 N$

The maximum power will be applied when the velocity is maximum, v = 2.20 m/s, and so it is:

$P=Fv=(4829)(2.20)=10624 W$

(c) $5.82\cdot 10^6 J$

Due to the law of conservation of energy, the total energy transferred out of the motor by work must be equal to the gravitational potential energy gained by the car.

The change in potential energy of the car is:

$\Delta U = mg \Delta h$