The problem describes the relationship of "bulb a" and "bulb b" to be in connected in series. When the switch is open then no current can flow, on the other hand, when it is closed, current will pass through.
When only "bulb a" is connected to the battery then more current is flowing to "bulb a" causing it to be bright.
Closing the switch would mean that "bulb b" is already included in the circuit and the battery will push small current to flow around the whole circuit. The more bulbs are connected, the harder for the current to flow because the resistance will be very high.
So the light of "bulb a" will be dimmer.
Answer: Trotting uses only 75 percent of the energy as galloping
Explanation: Trotting is only 300 J/m, whereas galloping is roughly 400 J/m
Explanation:
In Europe the standard voltage in homes is 220 V instead of the 120 V used in the United States.
100-W European bulb would be intended for use with a 220-V potential difference.
(a) If V = 220 V and P = 100 W
Power :

If you bring a "100-W" European bulb home to the untied States, what should be its US power rating. So,

or
P = 29.8 watts
(b) Let I is the current will the 100-W European bulb draw in normal use in the United States. So,

Hence, this is the required solution.
sunlight, and the position of the earth
Answer:
Yes, if the carts are travelling into opposite directions
Explanation:
The total momentum of a two carts system is the sum of the momenta of the individual carts:

where
m1, m2 are the masses of the two carts
v1, v2 are the velocities of the two carts
In order to have a total momentum of zero, we must have
(1)
Let's remind that velocity (and so, momentum as well) is a vector quantity: this means that it has a direction, so when summing together the momenta, we must also consider the sign of the velocity, depending on its direction.
Therefore, if the two carts are moving in opposite directions, the signs of the two velocities will be opposite. For example, we can have

This means that the condition in eq.(1) can be satisfied, provided that the two carts are travelling into opposite directions.