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-Dominant- [34]

3 years ago

14

you're riding on a train that's moving at 5 km/h and you roll a ball down the aisle at 2 km/h in the same direction as the train

is moving. if a person standing on the ground near the train track could see the ball how fast would it appear moving

1 answer:

jekas [21]3 years ago

3 0

Just add the 2 and 5.
7 km/h

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The aurora is caused when electrons and protons, moving in the earth's magnetic field of ≈5.0×10−5T, collide with molecules of t

Vika [28.1K]

Answer:

$r=0.341m$

Explanation:

The circular movement is produced by the magnetic field:

$F=q*v*B$

This force is a centripetal force because the electron moves in a plane perpendicular to the magnetic field. For a centripetal Force, that produces a circular orbit with a radius r:

$F=m*a=m*v^{2}/r$

If we solve these two equations in order to find r, with the mass and charge of a electron:

$qvB=mv^{2}/r\\r=mv/(qB)=9,1*10^{-31}*3*10^{6}/(1.6*10^{-19}*5*10^{-5})=0.341m$

3 0

3 years ago

A golfer hits a shot to a green. The ball leaves the club at a speed of 20 m/s at an angle 32° above the horizontal. It rises to

Daniel [21]

Answer:

16.96 m/s

Explanation:

It is the case of projectile motion in which the projectile fires from the ground and again it hit the ground.

The angle of projection is 32 degree and the velocity of projection is 20 m/s

he velocity at the maximum height is equal to the horizontal component of velocity which always remains constant as there is no acceleration along x axis.

Velocity at the highest point = u Cos 32 = 20 x Cos 32 = 16.96 m/s

4 0

3 years ago

Looking straight downward into a rain puddle whose surface is covered with a thin ﬁlm of gasoline. you notice a swirlingpattern

Helen [10]

Answer:

Explanation:

In case of colored film we apply the theory of interference.

Condition that colored fringe is formed ( constructive interference)

2μt = λ/ 2 ( minimum order)

t = λ/ 4μ

= 540 / 4 x 1.38

= 97.83 nm

4 0

3 years ago

Two vertical springs have identical spring constants, but one has a ball of mass m hanging from it and the other has a ball of m

OverLord2011 [107]

To solve this problem we will start from the definition of energy of a spring mass system based on the simple harmonic movement. Using the relationship of equality and balance between both systems we will find the relationship of the amplitudes in terms of angular velocities. Using the equivalent expressions of angular velocity we will find the final ratio. This is,

The energy of the system having mass m is,

$E_m = \frac{1}{2} m\omega_1^2A_1^2$

The energy of the system having mass 2m is,

$E_{2m} = \frac{1}{2} (2m)\omega_1^2A_1^2$

For the two expressions mentioned above remember that the variables mean

m = mass

$\omega =$ Angular velocity

A = Amplitude

The energies of the two system are same then,

$E_m = E_{2m}$

$\frac{1}{2} m\omega_1^2A_1^2=\frac{1}{2} (2m)\omega_1^2A_1^2$

$\frac{A_1^2}{A_2^2} = \frac{2\omega_2^2}{\omega_1^2}$

Remember that

$k = m\omega^2 \rightarrow \omega^2 = k/m$

Replacing this value we have then

$\frac{A_1}{A_2} = \sqrt{\frac{2(k/m_2)}{(k/m_1)^2}}$

$\frac{A_1}{A_2} = \sqrt{2} \sqrt{\frac{m_1}{m_1}}$

But the value of the mass was previously given, then

$\frac{A_1}{A_2} = \sqrt{2} \sqrt{\frac{m}{2m}}$

$\frac{A_1}{A_2} = \sqrt{2} \sqrt{\frac{1}{2}}$

$\frac{A_1}{A_2} = 1$

Therefore the ratio of the oscillation amplitudes it is the same.

5 0

3 years ago

Which body system regulates and control the digestive system

maw [93]

Which body system regulates and control the digestive system

the circulatory system

hope this help

8 0

4 years ago