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3 years ago

Ahdksbdsje I need help

Physics

1 answer:

harina [27]3 years ago

4 0

8). B
Note: This is only true if the additional battery is added in SERIES
with the original one. Then the voltage to the motor is increased,
and the motor runs faster.
If instead you add another battery in parallel with the original one,
the voltage to the motor doesn't change, and neither does its speed.
The batteries just last longer.

9). A

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How can a magnetic feild be used to generate an electric current

ziro4ka [17]

The correct answer is A) When a magnet moves near a wire, it's charging field causes the electrons in the wire to flow as electric current

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3 years ago

A figure skater begins spinning counterclock-

wlad13 [49]

Answer:

Angular acceleration, $\alpha =0.64\ rad/s^2$

Explanation:

Given that,

Initial angular velocity, $\omega_i=4.67\ rad/s$

The final angular velocity, $\omega_f=7.37\ rad/s$

Time, t = 4.2 s

We need to find her average angular acceleration during this time interval. Acceleration is the rate of change of velocity. So,

$\alpha =\dfrac{\omega_f-\omega_i}{t}\\\\\alpha =\dfrac{7.37-4.67}{4.2}\\\\\alpha =0.64\ rad/s^2$

So, her average angular acceleration is $0.64\ rad/s^2$ .

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3 years ago

Rays traveling parallel to the principle axis of a concave mirror will reflect out through the mirrors focus?

abruzzese [7]

Answer:

True

Explanation:

When a ray travelling parallel to the principle axis of a concave mirror then the light ray reflect out through the mirrors and passing through the focus.

When a light ray travelling through focus of a concave mirror then after reflection the light ray reflect out through the mirror and go parallel to principle axis.

Therefore, rays travelling parallel to the principle axis of a concave mirror will reflect out through the mirrors focus.

It is true.

7 0

4 years ago

Read 2 more answers

A long string is pulled so that the tension in it increases by a factor of four. If the change in length is negligible, by what

rusak2 [61]

To solve this problem we will apply the concepts related to wave velocity as a function of the tension and linear mass density. This is

$v = \sqrt{\frac{T}{\mu}}$

Here

v = Wave speed

T = Tension

$\mu$ = Linear mass density

From this proportion we can realize that the speed of the wave is directly proportional to the square of the tension

$v \propto \sqrt{T}$

Therefore, if there is an increase in tension of 4, the velocity will increase the square root of that proportion

$v \propto \sqrt{4} = 2$

The factor that the wave speed change is 2.

3 0

3 years ago

Large electric fields in cell membranes cause ions to move through the cell wall. The field strength in a typical membrane is 1.

BlackZzzverrR [31]

1) Magnitude of the force: $1.6\cdot 10^{-12} N$

The magnitude of the electric force on an electric charge is:

$F=qE$

where q is the charge and E the electric field. In this problem:

$q = +e = +1.6\cdot 10^{-19} C$ is the charge of the calcium ion

$E=1.0 \cdot 10^7 N/C$ is the magnitude of the electric field

Substituting,

$F=(1.6\cdot 10^{-19}C)(1.0\cdot 10^7 N/C)=1.6\cdot 10^{-12} N$

2) Acceleration: $2.5\cdot 10^{13} m/s^2$

The atomic mass of a calcium ion is approx. 40 a.m.u, this means that its mass is

$m=40 \cdot (1.6\cdot 10^{-27}kg)=6.4\cdot 10^{-26} kg$

And so, the acceleration of the ion is given by Newton's second law:

$a=\frac{F}{m}=\frac{1.6\cdot 10^{-12}N}{6.4\cdot 10^{-26} kg}=2.5\cdot 10^{13} m/s^2$

3) Yes

Explanation: a particle with same charge (+e) of the calcium ion could have the same acceleration of the calcium ion if it has exactly the same mass. In fact, the acceleration depends only on two factors: the mass and the force, so it both are the same, than the acceleration does not change.

4) The mass of the particle

In fact, the acceleration of the particle is given by:

$a=\frac{F}{m}$

where F is the electric force and m the mass. Therefore, if the mass changes ,the acceleration changes as well.

4 0

3 years ago