What is the speed of light ?

A group of students are playing tug-of-war. The students on both

Andrews [41]

Answer:

newton's first law

Explanation:

this is because newton's first law of motion states that every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it.

hope this helps, if you want more elaboration, tell me

7 0

2 years ago

Jack (mass 59.0 kg ) is sliding due east with speed 8.00 m/s on the surface of a frozen pond. He collides with Jill (mass 47.0 k

Phantasy [73]

Answer:

Part(A): The magnitude of Jill's final velocity is $\bf{6.59~m/s}$ .

Part(B): The direction is $\bf{42.7^{0}}$ south to east.

Explanation:

Given:

Mass of Jack, $m_{1} = 59.0~Kg$

Mass of Jill, $m_{2} = 47..0~Kg$

Initial velocity of Jack, $v_{1i} = 8.00~m/s$

Initial velocity of Jill, $v_{2i} = 0$

Final velocity of Jack, $v_{1f} 5.00~m/s$

The final angle made by Jack after collision, $\alpha = 34.0^{0}$

Consider that the final velocity of Jill be $v_{2f}$ and it makes an angle of $\beta$ with respect to east, as shown in the figure.

Conservation of momentum of the system along east direction is given by

$~~~~&& m_{1}v_{1i} + m_{2}v_{2i} = m_{1}v_{1f} \cos \alpha + m_{2}v_{2f}^{x}\\&or,& v_{2f}^{x} = \dfrac{m_{1}(v_{1i} - v_{1f} \cos \alpha)}{m_{2}}$

where, $v_{2f}^{x}$ is the component of Jill's final velocity along east. The direction of this component will be along east.

Substituting the value, we have

$v_{2f}^{x} &=& \dfrac{(59.0~Kg)(8.00~m/s - 5.00 \cos 34.0^{0}~m/s)}{47.0~Kg}\\~~~~~&=& 4.84~m/s$

Conservation of momentum of the system along north direction is given by

$~~~~&& v_{2f}^{y} + v_{1f} \sin \alpha = 0\\&or,& v_{2f}^{y} = - v_{1f} \sin \alpha = (8.00~m/s) \sin 34^{0} = 4.47~m/s$

where, $v_{2f}^{y}$ is the component of Jill's final velocity along north. The direction of this component will be along the opposite to north.

Part(A):

The magnitude of the final velocity of Jill is given by

$v_{2f} &=& \sqrt{(v_{2f}^{x})^{2} + (v_{2f}^{y})^{2}}\\~~~~~&=& 6.59~m/s$

Part(B):

The direction is given by

$\beta &=& \tan^{-1}(\dfrac{4.47~m/s}{4.84~m/s})\\~~~~&=& 42.7^{0}$

4 0

3 years ago

What is stellar parallax?a.It describes the fact that stars are actually moving relative to one another, even though to our eyes

bagirrra123 [75]

Answer:

Option C

C. It is the slight back-and-forth shifting of star positions that occurs as we view the stars from different positions in Earth's orbit of the Sun.

Explanation:

The angle due to the change in position of a nearby object against the background stars it is known as parallax.

The parallax angle can be used to find out the distance by means of triangulation. Making a triangle between the nearby star, the Sun and the Earth(as is shown in the image below), knowing that the distance between the Earth and the Sun (150000000 Km) is defined as 1 astronomical unit.

$d(pc) = \frac{1}{p('')}$ (1)

Equation (1) represents the distance in a unit known as parsec (pc).

Key terms:

Parsec: Parallax of arc second

3 0

3 years ago

Find the number of free electrons per cubic centimeter in germanium at room temperature given that there are 5.6x10-10 free elec

charle [14.2K]

Answer:

$2.41 \times 10^{13}\ free\ electrons/cm^3$

Explanation:

given,

free electron per atom = 5.6 x 10⁻¹⁰

density of silicon = 5.32 g/cm³

molar mass of silicon = 72.59 g/mol

number of moles per cubic centimeter

= $\dfrac{5.32}{72.59}\ mole/cm^3$

number of atom per cubic centimeter

= $\dfrac{5.32}{72.59}\times 6.022 \times 10^{23}\ /cm^3$

number of free electron per cubic centimeter

= $\dfrac{5.32}{72.59}\times 6.022 \times 10^{23}\times 5.6 \times 10^{-10}/cm^3$

= $2.41 \times 10^{13}\ free\ electrons/cm^3$

5 0

3 years ago

How is temperature related to the physical change of a<br> substance?

sveticcg [70]

Explanation:

temperature can cause change of state of a substance and change of state is a physical change. A physical change simply put is a change that isn't permanent...a change that can be reversed. the change of state of a substance is a physical change because addition of heat or a rise in temperature makes a solid melt and the removal of heat turns it back to solid

3 0

3 years ago

What is the speed of light ?​

What is the speed of light ?