I believe the answer is c
Answer:
The magnetic field will be
, '2d' being the distance the wires.
Explanation:
From Biot-Savart's law, the magnetic field (
) at a distance '
' due to a current carrying conductor carrying current '
' is given by

where '
' is an elemental length along the direction of the current flow through the conductor.
Using this law, the magnetic field due to straight current carrying conductor having current '
', at a distance '
' is given by

According to the figure if '
' be the current carried by the top wire, '
' be the current carried by the bottom wire and '
' be the distance between them, then the direction of the magnetic field at 'P', which is midway between them, will be perpendicular towards the plane of the screen, shown by the
symbol and that due to the bottom wire at 'P' will be perpendicular away from the plane of the screen, shown by
symbol.
Given
and 
Therefore, the magnetic field (
) at 'P' due to the top wire

and the magnetic field (
) at 'P' due to the bottom wire

Therefore taking the value of
the net magnetic field (
) at the midway between the wires will be

Answer:
a baseball flying through the air at 90 miles per hour
Explanation:
For the question, Therefore, the kinetic energy of an object is proportional to the square of its velocity (speed). In other words, If the velocity is doubled the kinetic energy will increase by a factor of four.
Answer:
Explanation:
Comment
You could calculate it out by assuming the same starting temperature for each substance. (You have to assume that the substances do start at the same temperature anyway).
That's like shooting 12 with 2 dice. It can be done, but aiming for a more common number is a better idea.
Same with this question.
You should just develop a rule. The rule will look like this
The greater the heat capacity the (higher or lower) the change in temperature.
The greater the heat capacity the lower the change in temperature
That's not your question. You want to know which substance will have the greatest temperature change given their heat capacities.
Answer
lead. It has the smallest heat capacity and therefore it's temperature change will be the greatest.