Answer:
william h. seward secured the purchase of alaska from:
Explanation:
Answer:
C) upward
Explanation:
The problem can be solved by using the right-hand rule.
First of all, we notice at the location of the negatively charged particle (above the wire), the magnetic field produced by the wire points out of the page (because the current is to the right, so by using the right hand, putting the thumb to the right (as the current) and wrapping the other fingers around it, we see that the direction of the field above the wire is out of the page).
Now we can apply the right hand rule to the charged particle:
- index finger: velocity of the particle, to the right
- middle finger: direction of the magnetic field, out of the page
- thumb: direction of the force, downward --> however, the charge is negative, so we must reverse the direction --> upward
Therefore, the direction of the magnetic force is upward.
Answer:
Q = 29.4 x 10⁻⁹ C.
Explanation:
Electric field due to a charge Q at distance d is given by coulomb law as follows
Electric field
E = k Q /d²
where for air k which is a constant is 9 x 10⁹
Given E = 32.08 , d = 2.84 m
Putting these values in the relation above, we have
![[tex]32.08=\frac{9\times 10^9\times Q}{(2.84)^2}](https://tex.z-dn.net/?f=%5Btex%5D32.08%3D%5Cfrac%7B9%5Ctimes%2010%5E9%5Ctimes%20Q%7D%7B%282.84%29%5E2%7D)
[/tex]
Q = 29.4 x 10⁻⁹ C.
f' = frequency observed by the police car after sound reflected from the vehicle and comes back to police car = 1250 Hz
f = frequency emitted by the police car = 1200 Hz
V = speed of sound = 340 m/s
v = speed of vehicle = ?
frequency observed by the police car is given as
f' = f (V + v)/(V - v)
inserting the values in the above equation
1250 = 1200 (340 + v)/(340 - v)
v = 6.9 m/s
