Answer:
Sound waves travel faster in a low-density gas
Explanation:
First of all, let's remind that sound waves are pressure waves: they consist of oscillations of the particles in a medium, which oscillate back and forth along the direction of motion of the wave (longitudinal wave).
The speed of sound in an ideal gas is given by the equation

where
is the adiabatic index of the gas
p is the gas pressure
is the gas density
From the equation, we see that the speed of sound is inversely proportional to the square root of the density: therefore, the lower the density, the faster the sound waves.
So, sound waves will travel faster in a low-density gas.
Answer:
The magnitude of the magnetic force this particle experiences is
.
Explanation:
Given that,
Velocity v= (3i-5j+k) m/s
Magnetic field B=(i+2j-k) T
We need to calculate the value 

We need to calculate the magnitude of the magnetic force this particle experiences
Using formula of magnetic force

Put the value into the formula



Hence, The magnitude of the magnetic force this particle experiences is
.

Distance travelled by the truck is ~
And it's displacement is ~

See the diagram in attachment for reference ~
Let O be the initial point, It travels 60 km towards west till point B and then 80 km towards north till point P and returns to initial point O in a straight line, now as we can observe here, it forms a right angled Triangle.
The measure of two legs is 60 km and 80 km, let's find the hypotenuse ~
According to Pythagoras theorem ~
hypotenuse² = sum of squares of other two legs
that is ~
So, the distance between the point A and O is 100 km
Now, The total distance is equal to the distance covered through actual path that is ~
And displacement is the distance between the final point and initial point, but since the truck returns to the point from where it started the journey, so the final and initial point is same therefore displacement is equal to 0.
M = 150 kg.
Final velocity, v = 14 m/s
Initial Velocity, u = 6 m/s
Impulse = <span> m(v - u)</span>
= 150*(14 - 6)
= 150*8 = 1200 kgm/s or 1200 Ns<span> </span>
When two stars are bound together gravitationally and orbit a common mass, theyre known as B. BINARY STARS.