<span>Answer:
So it gets to the top of the ramp and stops. The parallel force pushing it down the ramp is mg sin θ, but for it to move, the frictional force must be overcome. This frictional force is μmg cos θ, where μ is the coefficient of static friction. For movement, then,
mg sin θ > μmg cos θ ==> tan θ > μ ==> θ > arctan 0.5 = 26.565° ==> θ = 27°</span>
The second major reason for the difference in gravity at differentlatitudes is that the Earth's equatorial bulge (itself also caused by centrifugalforce from rotation) causes objects at the Equator to be farther from the planet's centre than objects at the poles.
Answer: q = -52.5 μC
Explanation:
The complete question is given thus;
A point charge Q moves on the x-axis in the positive direction with a speed of 280 m/s. A point P is on the y-axis at y=+70mm. The magnetic field produced at the point P, as the charge moves through the origin, is equal to -0.30uTk. What is the charge Q? (uo=4pi x 10^-7 T m/A).
SOLVING:
from the given parameters we can solve this problem.
Given that the
Speed = 280 m/s
y = 70mm
B = -30 * 10⁻⁶T
Using the equation for magnetic field we have;
Β = μqv*r / 4πr²
making q (charge) the subject of formula we have that;
q = B * 4 *πr² / μqv*r
substituting the values gives us
q = (-0.3*10⁻⁶Tk * 4π * 0.07²) / (4π*10⁻⁷ * 280 ) = - [14.7 * 10⁻¹⁰k / 2.8 * 10⁻⁵ k ]
q = -52.5 μC
cheers i hope this helped !!!