Answer:
The number of revolutions turned by the centrifuge is 8250 revolutions.
Explanation:
Given;
number of revolution per minutes, ω = 15000 rpm
time of motion, t = 330 s = 5.5 minutes
The number of revolutions turned by the centrifuge is given by;

Therefore, the number of revolutions turned by the centrifuge is 8250 revolutions.
Answer:
1)
from the positive x-axis.
2) 
Explanation:
Given:
speed of rowing in still water, 
1)
speed of water stream, 
we know that the direction of resultant of the two vectors is given by:

where:
the angle of resultant vector from the positive x-axis.
angle between the given vectors
When the rower wants to reach at the opposite end then:

so,




from the positive x-axis.
2)
Now the resultant velocity of rowing in the stream:



Therefore time taken to cross a 4 miles wide river:



Hope this answer helps, cause Idk, I might be wrong, but I still, I used the correct formulas, so I might be correct
Answer:
light and sound are both trasverse waves
Explanation:
Answer:
E = 5.65 x 10¹⁰ N/C
Explanation:
First we need to find the total charge on the sphere. So, we use the following formula for that purpose:

where,
q = total charge on sphere
V = Volume of Sphere = 
σ = volume charge density = 1.5 C/m³
Therefore,

Now, we use the following formula to find the electric field due to this charged sphere:

where.
E = Electric Field Magnitude = ?
k = Coulomb's Constant = 9 x 10⁹ N.m²/C²
r = radius of sphere = 8 cm = 0.08 m
Therefore,

<u>E = 5.65 x 10¹⁰ N/C</u>