The electric field generated by a point charge is given by:
where
is the Coulomb's constant
Q is the charge
r is the distance from the charge
We want to know the net electric field at the midpoint between the two charges, so at a distance of r=5.0 cm=0.05 m from each of them.
Let's calculate first the electric field generated by the positive charge at that point:
where the positive sign means its direction is away from the charge.
while the electric field generated by the negative charge is:
where the negative sign means its direction is toward the charge.
If we assume that the positive charge is on the left and the negative charge is on the right, we see that E1 is directed to the right, and E2 is directed to the right as well. This means that the net electric field at the midpoint between the two charges is just the sum of the two fields:
Momentum of car
Given: Mass m= 1,400 Kg; V = 6.0 m/s
Formula: P = mv
P = (1,400 Kg)(6.0 m/s)
P = 8,400 Kg.m/s
Velocity of the rider to have the same momentum as a car.
Mass of rider and bicycle m = 100 Kg
P = mv
V = P/m
V = 8,400 Kg.m/s/100 Kg
V = 84 m/s
Answer:
D) wood rubbed against a rough surface feels hot
Explanation:
The heat is transferred from one form of energy (friction of the wood being rubbed against the surface) to another (heat energy).
At the entrance of most beaches, there is a bulletin board with notices about water conditions: maybe a faded sign warning about rip currents and a list of this week's tide tables. Most people pass them by without a second thought, but if you want to enter the ocean, it is important to know its movements, whether to avoid being caught in a riptide or to figure out when the waves will be at their best.
Hope this helps