<span>Unless the pig moves static friction acts on it once the pig starts moving kinetic friction comes in to play so when the pig is not moving=frictional force acting on it =normal force*co-efficient of static friction.</span>
Answer:
Approximately
(given that the magnitude of this charge is
.)
Explanation:
If a charge of magnitude
is placed in an electric field of magnitude
, the magnitude of the electrostatic force on that charge would be
.
The magnitude of this charge is
. Apply the unit conversion
:
.
An electric field of magnitude
would exert on this charge a force with a magnitude of:
.
Note that the electric charge in this question is negative. Hence, electrostatic force on this charge would be opposite in direction to the the electric field. Since the electric field points due south, the electrostatic force on this charge would point due north.
Answer:
Approximately
for the train from Boston to NYC Penn Station.
Approximately
for the train from NYC Penn Station to Boston.
Explanation:
Convert minutes to hours:
.
.
Calculate average speed of each train:
.

Assume that it takes a time period of
for the trains to pass by each other after departure. Distance each train travelled would be:
.
.
Since the trains have just passed by each other, the sum of the two distances should be equal to the distance between the stations:
.
Rearrange and solve for
:
.
.
Distance each train travelled in
:
.
.
Answer: A. Object A will have a positive charge.
Explanation: If the number of protons and electrons are the same, their net charges cancel each other out, and you have a neutral charge. If electrons are transferred to another object, the amount of positive charge will outweigh the amount of negative charge. As a result, you are left with an overall positive charge in object A. Meanwhile, object B is now negative.