Frequency is 1/period. f=1/0.5 = 2Hz
Answer:
no
Explanation
non-metal and metal are two different things
The total force is the vector sum of the individual forces. The force from either electron has the same magnitude at the midpoint, but the directions of the forces are opposite, so the sum of the two forces is zero. I hope this helps! Thanks
Answer:
B.The force of friction between the block and surface will decrease.
Explanation:
The force of friction is given by
where 
is the coefficient of friction and 
is the normal force.
When the student pulls on the block with force 
at an angle 
, the normal force on the block becomes
and hence the frictional force becomes
.
Now, as we increase , 
increases which as a result decreases the normal force 
, which also means the frictional force decreases; Hence choice B stands true.
<em>P.S: Choice D is tempting but incorrect since the weight </em>
<em> is independent of the external forces on the block. </em>
