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3 years ago

If the voltage impressed across a circuit is held constant while the resistance is halved, what change occur?

Physics

1 answer:

egoroff_w [7]3 years ago

3 0

Answer:

The current doubles

Explanation:

In a circuit, Ohm's law gives the relationship between voltage, current and resistance:

$V=RI$

where

V is the voltage

R is the resistance

I is the current

In this problem,

V is held constant

R is halved: $R'=\frac{R}{2}$

Therefore, the new current is

$I'=\frac{V}{R'}=\frac{V}{R/2}=2\frac{V}{R}=2I$

So, the current doubles.

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All of the following are categories of individual activities except?

aliina [53]

B. Hand-eye Coordination because it can be used in multiple activities

3 0

2 years ago

A steel ball rolls with a constant velocity on a tabletop 0.950 m high it rolls off and hit the ground 0.352 m from the edge of

sp2606 [1]

Answer:

0.799 m/s if air resistance is negligible.

Explanation:

For how long is the ball in the air?

Acceleration is constant. The change in the ball's height $\Delta h$ depends on the square of the time:

$\displaystyle \Delta h = \frac{1}{2} \;g\cdot t^{2} + v_0\cdot t$ ,

where

$\Delta h$ is the change in the ball's height.
$g$ is the acceleration due to gravity.
$t$ is the time for which the ball is in the air.
$v_0$ is the initial vertical velocity of the ball.

The height of the ball decreases, so this value should be the opposite of the height of the table relative to the ground. $\Delta h = -0.950\;\text{m}$ .
Gravity pulls objects toward the earth, so $g$ is also negative. $g \approx -9.81\;\text{m}\cdot\text{s}^{-2}$ near the surface of the earth.
Assume that the table is flat. The vertical velocity of the ball will be zero until it falls off the edge. As a result, $v_0 = 0$ .

Solve for $t$ .

$\displaystyle \Delta h = \frac{1}{2} \;g\cdot t^{2} + v_0\cdot t$ ;

$\displaystyle -0.950 = \frac{1}{2} \times (-9.81) \cdot t^{2}$ ;

$\displaystyle t^{2} =\frac{-0.950}{1/2 \times (-9.81)}$ ;

$t \approx 0.440315\;\text{s}$ .

What's the initial horizontal velocity of the ball?

Horizontal displacement of the ball: $\Delta x = 0.352\;\text{m}$ ;
Time taken: $\Delta t = 0.440315\;\text{s}$

Assume that air resistance is negligible. Only gravity is acting on the ball when it falls from the tabletop. The horizontal velocity of the ball will not change while the ball is in the air. In other words, the ball will move away from the table at the same speed at which it rolls towards the edge.

$\begin{aligned}\text{Rolling Velocity}&=\text{Horizontal Velocity} \\&= \text{Average Horizontal Velocity}\\ &=\frac{\Delta x}{\Delta t}=\frac{0.352\;\text{m}}{0.440315\;\text{s}}=0.0799\;\text{m}\cdot\text{s}^{-1}\end{aligned}$ .

Both values from the question come with 3 significant figures. Keep more significant figures than that during the calculation and round the final result to the same number of significant figures.

3 0

2 years ago

What type of heat transfer is used to fry an egg in a pan and how can you tell?

Deffense [45]

Answer: Option (B) is the correct answer.

Explanation:

A process in which transfer of heat occurring when one object touches another object is known as conduction.

For example, when a pan is heated and then an egg is placed over the pan. Then there will be transfer of heat from pan towards the egg.

As a result, the egg gets cooked because the egg was touching the pan.

Hence, we can conclude that it is conduction because the egg is touching the pan.

6 0

2 years ago