Which of the following occurs when light is reflected from a rough or unpolished surface

What is happening if energy input remains constant and voltage remains the same in a circuit, but the current decreases?

atroni [7]

The resistance of the circuit will definitely increase. This can be proved by the Ohm's Law where it is said that the potential difference across a conductor is directly proportional to the current and the proportionality constant is known as the resistance. The law is expressed as V = IR. As we can see, when the voltage remains constant while the current decreases then the resistance will increase.

3 0

3 years ago

Which of the following scenarios describes an object being acted on by a conservative force?

andrew11 [14]

Answer:

Option: A feather falls from one end of a tube to the other inside a vacuum.

Explanation:

To answer the question we need to first understand what is meant by Conservative Force.

In principle, Conservative forces are basically forces that are not affected by outside parameters (such as friction, air resistance etc). If the present force is strictly based on the initial and the final location of the object, with the inbetween path being irrelevant, the force will be conservative. A conservative force will be zero if we are looking at a closed path-system. We can also say that the system's energy loss will not be a function of the distance covered but is a function of displacement.

Looking at the available options, we can see that:

Option A: A woman hikes up a mountain to a point 20 feet above ground.

This is a Non Conservative force as this case does not depend just on displacement but also in the path in between, i.e. hiking up the mountain there will be other forces that will affect the woman such as air resistance.

Option B: A dishwasher was pulled up to a window by a rope, using a pulley system.

This is a Non Conservative force as this case does not depend just on displacement but also in the inbetween path along with the forces present in a pulley system such as friction.

Option C: A feather falls from one end of a tube to the other inside a vacuum.

This is a Conservative force as here we are looking at a vacuum and its a closed system of no other forces present due to vacuum. However, we CAN'T say that ALL forces in a Vacuum Are Conservative because there are cases of dynamic steady state fields where the system is prone to other forces (i.e. open system).

Option D: A puck glides across and slowly comes to a stop on an ice rink.

This is a Non Conservative force as this case does not depend just on displacement but also the motion until it comes to a stop, which is possibly due to the friction between the ice rink and the puck.

7 0

3 years ago

Determine the current I flowing through a solenoid, if the magnetic flux inside its core is found to be 1.30 10-4 Wb. The radius

inna [77]

Answer: The current I flowing through a solenoid is 11.6A

Explanation: Please see the attachments below

7 0

3 years ago

The vector sum of the forces acting on the beam is zero, and the sum of the moments about the left end of the beam is zero. (a)

Marysya12 [62]

This question is incomplete, the complete question is;

The vector sum of the forces acting on the beam is zero, and the sum of the moments about the left end of the beam is zero.

(a) Determine the forces and and the couple

(b) Determine the sum of the moments about the right end of the beam.

(c) If you represent the 600-N force, the 200-N force, and the 30 N-m couple by a force F acting at the left end of the beam and a couple M, what is F and M?

Answer:

a)

the x-component of the force at A is $A_{x}$ = 0

the y-component of the force at A is $A_{y}$ = 400 N

the couple acting at A is; $M_{A}$ = 146 N-m

b)

the sum of the momentum about the right end of the beam is; ∑ $M_{R}$ = 0

c)

the equivalent force acting at the left end is; F = -400J ( N)

the couple acting at the left end is; M = - 146 N-m

Explanation:

Given that;

The sum of the forces acting on the beam is zero ∑f = 0

Sum of the moments about the left end of the beam is also zero ∑ $M_{L}$ = 0

Vector force acting at A, $F_{A}$ = $A_{x}i$ + $A_{y}j$

Now, From the image, we have;

a)

∑f = 0

$F_{A}$ - 600j + 200j = 0i + 0j

$A_{x}i$ + $A_{y}j$ - 600j + 200j = 0i + 0j

$A_{x}i$ + ( $A_{y}$ - 400)j = 0i + 0j

now by equating i- coefficients'

$A_{x}$ = 0

so, the x-component of the force at A is $A_{x}$ = 0

also by equating j-coefficient

$A_{y}$ - 400 = 0

$A_{y}$ = 400 N

hence, the y-component of the force at A is $A_{y}$ = 400 N

we also have;

∑ $M_{L}$ = 0

$M_{A}$ - ( 30 N-m ) - ( 0.380 m )( 600 N ) + ( 0.560 m )( 200 N ) = 0

$M_{A}$ - 30 N-m - 228 N-m + 112 Nm = 0

$M_{A}$ - 146 N-m = 0

$M_{A}$ = 146 N-m

Therefore, the couple acting at A is; $M_{A}$ = 146 N-m

b)

The sum of the moments about right end of the beam is;

∑ $M_{R}$ = (0.180 m)(600N) - (30 N-m) - ( 0.56 m)( $A_{y}$ ) + $M_{A}$

∑ $M_{R}$ = (108 N-m) - (30 N-m) - ( 0.56 m)(400 N ) + 146 N-m

∑ $M_{R}$ = (108 N-m) - (30 N-m) - ( 224 N-m ) + 146 N-m

∑ $M_{R}$ = 0

Therefore, the sum of the momentum about the right end of the beam is; ∑ $M_{R}$ = 0

c)

The 600-N force, the 200-N force and the 30 N-m couple by a force F which is acting at the left end of the beam and a couple M.

The equivalent force at the left end will be;

F = -600j + 200j (N)

F = -400J ( N)

Therefore, the equivalent force acting at the left end is; F = -400J ( N)

Also couple acting at the left end

M = -(30 N-m) + (0.560 m)( 200N) - ( 0.380 m)( 600 N)

M = -(30 N-m) + (112 N-m) - ( 228 N-m))

M = 112 N-m - 258 N-m

M = - 146 N-m

Therefore, the couple acting at the left end is; M = - 146 N-m

7 0

2 years ago

What unit can be used to measure the mass of a grain of salt

Anna007 [38]

milligrams

Explanation:

The best unit to measure the mass of a grain of salt is the milligram.

This is about; a thousandth of a gram.

A grain of salt is a very small particle size that can still be visible with the eye.

It has a very low and small mass.

For substances like this, we use the milligram:

1000milligram = 1g

learn more:

Mass brainly.com/question/4736384

#learnwithBrainly

5 0

3 years ago