A group of a few thousand stars that are loosely held together by gravity is called a

The electrons in the beam of a television tube have a kinetic energy of 2.20 10-15 j. initially, the electrons move horizontally

dalvyx [7]

(a) The electrons move horizontally from west to east, while the magnetic field is directed downward, toward the surface. We can determine the direction of the force on the electron by using the right-hand rule:
- index finger: velocity --> due east
- middle finger: magnetic field --> downward
- thumb: force --> due north
However, we have to take into account that the electron has negative charge, therefore we have to take the opposite direction: so, the magnetic force is directed southwards, and the electrons are deflected due south.

b) From the kinetic energy of the electrons, we can find their velocity by using
$K= \frac{1}{2}mv^2$
where K is the kinetic energy, m the electron mass and v their velocity. Re-arranging the formula, we find
$v= \sqrt{ \frac{2K}{m} }= \sqrt{ \frac{2 \cdot 2.20 \cdot 10^{-15} J}{9.1 \cdot 10^{-31} kg} }=6.95 \cdot 10^7 m/s$

The Lorentz force due to the magnetic field provides the centripetal force that deflects the electrons:
$qvB = m \frac{v^2}{r}$
where
q is the electron charge
v is the speed
B is the magnetic field strength
m is the electron mass
r is the radius of the trajectory
By re-arranging the equation, we find the radius r:
$r= \frac{mv}{qB}= \frac{(9.1 \cdot 10^{-31} kg)(6.95 \cdot 10^7 m/s)}{(1.6 \cdot 10^{-19} C)(3.00 \cdot 10^{-5} T)}=13.18 m$

And finally we can calculate the centripetal acceleration, given by:
$a_c = \frac{v^2}{r}= \frac{(6.95 \cdot 10^7 m/s)^2}{13.18 m}=3.66 \cdot 10^{14} m/s^2$

5 0

3 years ago

an object has a momentum of 250 kg m/s what would be the momentum of an object that has half of the mass and going at the same v

Romashka-Z-Leto [24]

The momentum of the second object is 125 kg m/s

Explanation:

The momentum of an object is given by

$p=mv$

where

m is the mass of the object

v is its velocity

For the object in this problem,

$p = 250 kg m/s$

And its mass is m and its velocity is v.

The second object has a mass of $m' = \frac{m}{2}$ and same velocity v, so its momentum is

$p'=m'v = (\frac{m}{2})v=\frac{1}{2}(mv)=\frac{1}{2}p$

So, the second object has a momentum that is half of the momentum of the first object, therefore it is:

$p'=\frac{1}{2}(250)=125 kg m/s$

Learn more about momentum:

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#LearnwithBrainly

3 0

3 years ago

Why does the chord of an electric heater not glow while the heating element does

8_murik_8 [283]

Answer:

The heating element of the heater is made up of alloy which has very high resistance so when current flows through the heating element, it becomes too hot and glows red. But the resistance of cord which is usually of copper or aluminum is very low so it does not glow.

4 0

3 years ago

How do observing and inferring differ?

Illusion [34]

Observing is commenting on what you see e.g: It is raining.
Inferring is drawing conclusions from observations for example you see the road is wet so you might infer that it rained last night.

6 0

3 years ago

Read 2 more answers

A uniform, spherical, 1900.0 kg shell has a radius of 5.00 m. Find the gravitational force this shell exerts on a 1.80 kg point

Mandarinka [93]

Answer:

$F=9.09\times 10^{-9} N$