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3 years ago

A tree is fixed relative to Earth a tree is blank relative to the Sun

Physics

1 answer:

RUDIKE [14]3 years ago

8 0

moving,

the sun is a different "observer"

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If there is a break at any point in a series circuit the current will

Tomtit [17]

Answer:

not work

Explanation:

in a series circuit, everything meaning the electrons are flowing on one path, therefore, it wouldn continue to work.

8 0

2 years ago

A 0.73-m aluminum bar is held with its length parallel to the east-west direction and dropped from a bridge. Just before the bar

Tasya [4]

Answer:

A) B = 5.4 10⁻⁵ T, B) the positive side of the bar is to the West

Explanation:

A) For this exercise we must use the expression of Faraday's law for a moving body

fem = $- \frac{d \phi }{dt}$

fem = $- \frac{d (B l y}{dt}= - B l v$ - d (B l y) / dt = - B lv

B = $- \frac{fem}{l \ v}$

we calculate

B = - 7.9 10⁻⁴ /(0.73 20)

B = 5.4 10⁻⁵ T

B) to determine which side of the bar is positive, we must use the right hand rule

the thumb points in the direction of the rod movement to the south, the magnetic field points in the horizontal direction and the rod is in the east-west direction.

Therefore the force points in the direction perpendicular to the velocity and the magnetic field is in the east direction; therefore the positive side of the bar is to the West

4 0

2 years ago

a 5.0 kg ball is dropped from a 2.5 m high window. what is the velocity of the ball just before it hits the ground?

julsineya [31]

Answer:

Approximately $7.0\; \rm m \cdot s^{-1}$ .

Assumption: the ball dropped with no initial velocity, and that the air resistance on this ball is negligible.

Explanation:

Assume the air resistance on the ball is negligible. Because of gravity, the ball should accelerate downwards at a constant $g = 9.81 \; \rm m \cdot s^{-2}$ near the surface of the earth.

For an object that is accelerating constantly,

$v^2 - u^2 = 2\, a \, x$ ,

where

$u$ is the initial velocity of the object,
$v$ is the final velocity of the object.
$a$ is its acceleration, and
$x$ is its displacement.

In this case, $x$ is the same as the change in the ball's height: $x = 2.5\; \rm m$ . By assumption, this ball was dropped with no initial velocity. As a result, $u = 0$ . Since the ball is accelerating due to gravity, $a = 9.81\; \rm m \cdot s^{-2}$ .