At which location does the South Pole receive 24 hours of daylight?

You can see your image in front of mirror but not in the wall .why?

vivado [14]

Answer:

Because Bricks don't reflect. but mirrors reflect due to their lustre nature.

Explanation:

3 0

3 years ago

Two wires carrying equal currents exert a force ???????? on each other. (a) The current in each wire is doubled, while the dista

sweet-ann [11.9K]

a) The magnetic field created by a current-carrying wire is proportional to the current:

B ∝ I, B = magnetic field strength, I = current

The magnetic force acting on a current-carrying wire immersed in a magnetic field is proportional to the current and the magnetic field strength:

F ∝ IB, F = magnetic force, I = current, B = magnetic field strength

Let's focus on wire 1.

Since wire 2's current is doubled, wire 2 produces a magnetic field twice as strong as before.

Wire 1's current is also doubled, therefore we now have a wire having twice as strong a current immersed in twice as strong a magnetic field. The magnetic force on wire 1 (and you can make a similar argument for wire 2) will be four times as strong as before.

b) The general formula for the magnetic force acting on a current-carrying wire immersed in a magnetic field is given by:

F = IL×B

F = magnetic force vector

I = current

L = vector having a magnitude equal to wire length and representing direction of current

B = magnetic field vector

Note we are taking a cross product of the IL and B vectors, not the product of two scalar quantities.

The very nature of the cross product means that if L and B are parallel to each other, F = 0N

7 0

3 years ago

Daisy walks across a force platform, and forces exerted by her foot during a step are recorded. The peak velocity reaction force

Len [333]

Answer:

(a). The resultant of these forces is 1216.55 N.

(b). The direction of the resultant forces is 80.53°.

Explanation:

Given that,

First force = 1200 N

Second force = 200 N

(a). We need to calculate the resultant of these forces

Using cosine law

$F=\sqrt{F_{1}^2+F_{2}^2+2F_{1}F_{2}\cos\theta}$

Put the value into the formula

$F=\sqrt{1200^2+200^2+2\times1200\times200\cos90}$

$F=\sqrt{1200^2+200^2}$

$F= 1216.55\ N$

The resultant of these forces is 1216.55 N.

(b). We need to calculate the direction of the resultant forces

Using formula of direction

$\tan\alpha=\dfrac{F_{1}}{F_{2}}$

Put the value into the formula

$\alpha=\tan^{-1}(\dfrac{1200}{200})$

$\alpha=80.53^{\circ}$

Hence, (a). The resultant of these forces is 1216.55 N.

(b). The direction of the resultant forces is 80.53°.

4 0

4 years ago

Read 2 more answers

A(n) 69.8 kg astronaut becomes separated from the shuttle, while on a space walk. She finds herself 60.4 m away from the shuttle

alukav5142 [94]

Answer:

The time taken is 6.7 min

Explanation:

Using the linear momentum conservation theorem, we have:

$m_1*v_{o1}+m_2*v_{o2}=m_1*v_{f1}+m_2*v_{f2}$

when she was 60.4m from the shuttle, she has zero speed, so the initial velocity is zero.

$m_1*0+m_2*0=m_1*v_{f1}+m_2*v_{f2}\\m_1*_{f1}=-m_2*v_{f2}\\v_{f1}=-\frac{m_2*v_{f2}}{m_1}\\\\v_{f1}=-\frac{0.886kg*12m/s}{69.8kg}\\\\V_{f1}=-0.15m/s$

That is 0.15m/s in the opposite direction of the camera.

the time taken to get to the shuttle is given by:

$t=\frac{d}{v_{f1}}\\\\t=\frac{60.4m}{0.15m/s}\\\\t=403s\\t_{min}=403s*\frac{1min}{60s}=6.7min$

6 0

4 years ago

What is the kinetic energy of a an 80kg football player running at 8 m/s?

Ugo [173]

In the question it is already given that the football player is 80 kg.
Then the mass of the football player = 80 kg
Velocity at which the football player is running = 8 m/s
Kinetic Energy = 0.5 • mass • square of velocity
Now we have to put the known data in this equation to find the actual velocity of the footballer.
 So
Kinetic Energy of the footballer = 0.5 * 80 * (8 * 8)
= 0.5 * 80 * 64
= 2560
So the Kinetic energy of the footballer is 2560 joules

4 0

4 years ago