The
speed of sound depends on any form of matter or medium in which sound travels
through it and depends on the amount of molecular collisions. Sound travels slowest in gas in the form of steam
because the sound has to move around the gas molecules that are far apart making
it harder for the
energy of vibrations hit the particles and make sound.
Moreover,
sound travelling through solids like ice is much faster because the particles
are closer together so the sound waves do not have to travel that far making the
number of collisions greater and sound spread more easily.
Answer:
54mph
Explanation:
Speed is defined as the change in distance of a body with respect to time.
Let x be the speed of Eric on his way to the football game, if he used 11hours to the football game, his distance will be the product of his speed and time taken i.e
Distance = speed × time
Distance= x × 11
Distance = 11x... (1)
During his return journey, his speed increases by 12mph with a return drive in only 9hours i.e speed = x+12 and time is 9hours
Since distance = speed × time (return Journey)
Distance = (x+12)×9
Distance = 9x+84...(2)
Note that the distance to and fro the journey is the same as such we will equate equations 1 and 2 to get his initial speed "x" to have;
11x = 9x+84
11x-9x = 84
2x = 84
x = 42mph
This means that his initial speed on his way to the football game is 42mph. Since his speed increases by 12mph during his return drive, his return speed will be 42mph + 12mph which gives 54mph.
Answer:
Explanation:
Given that,
Force is downward I.e negative y-axis
F = -2 × 10^-14 •j N
Magnetic field is westward, +x direction
B = 8.3 × 10^-2 •i T
Charge of an electron
q = 1.6 × 10^-19C
Velocity and it direction?
Force in a magnetic field is given as
F = q(V×B)
Angle between V and B is 270, check attachment
The cross product of velocity and magnetic field
F =qVB•Sin270
2 × 10^-14 = 1.6 × 10^-19 × V × 8.3 × 10^-2
Then,
v = 2 × 10^-14 / (1.6 × 10^-19 × 8.3 × 10^-2)
v = 1.51 × 10^6 m/s
Direction of the force
Let x be the direction of v
-F•j = v•x × B•i
From cross product
We know that
i×j = k, j×i = -k
j×k =i, k×j = -i
k×i = j, i×k = -j OR -k×i = -j
Comparing -k×i = -j to given problem
We notice that
-F•j = q ( -V•k × B×i)
So, the direction of V is negative z- direction
V = -1.51 × 10^6 •k m/s
<u>Answer:</u>
The altitude of planet = 5989.198 km
<u>Explanation:</u>
We know that centripetal acceleration, 
, where v is the velocity and r is the radius. In this case both acceleration and velocity is given, so we can find radius of satellite.
v = 
a = 
So, 
We have diameter of earth = 12713 km
Radius of earth = 12713/2 = 6356.5 km
The altitude of planet = Radius of planet - radius of earth
= 12345.698 - 6356.5
= 5989.198 km
