Answer: To isolate the unknown substances, of which only tiny amounts were present, the Curies were the first to use a new method of chemical analysis. They employed various standard (but sometimes demanding) chemical procedures to separate the different substances in pitchblende.
Explanation:
Answer:
(a). The strength of the magnetic field is 0.1933 T.
(b). The magnetic flux through the loop is zero.
Explanation:
Given that,
Radius = 11.9 cm
Magnetic flux 
(a). We need to calculate the strength of the magnetic field
Using formula of magnetic flux





Put the value into the formula


(b). If the magnetic field is directed parallel to the plane of the loop,
We need to calculate the magnetic flux through the loop
Using formula of flux

Here, 


Hence, (a). The strength of the magnetic field is 0.1933 T.
(b). The magnetic flux through the loop is zero.
Answer:
the final velocity of the two blocks is
the distance that A slides relative to B is
Explanation:
From the diagram below;
acceleration of A relative to B is : 
where
v = u + at

Making t the subject of the formula; we have:


which implies the distance that A slides relative to B.
The final velocities of the two blocks can be determined as follows:
v = u + at

Thus, the final velocity of the two blocks is
8. In soft magnetic materials such as iron, what happens when an external magnetic field is removed?
a. The domain alignment persists.
b. The orientation of domains fluctuates.
c. The material becomes a hard magnetic material.
d. The orientation of domains changes, and the material returns to an unmagnetized state.
9. According to Lenz’s law, if the applied magnetic field changes,
a. the induced field attempts to keep the total field strength constant.
b. the induced field attempts to increase the total field strength.
c. the induced field attempts to decrease the total field strength.
d. the induced field attempts to oscillate about an equilibrium value.
10. The direction of the force on a current-carrying wire in an external magnetic field is
a. perpendicular to the current only.
b. perpendicular to the magnetic field only.
c. perpendicular to the current and to the magnetic field.
d. parallel to the current and to the magnetic field
Answer: Their final relative velocity is -0.412 m/s.
Explanation:
According to the law of conservation,

Putting the given values into the above formula as follows.



v = 
= -0.412 m/s
Thus, we can conclude that their final relative velocity is -0.412 m/s.