Answer:
I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.
Answer:
The ball thrown downward
Explanation:
When the ball is thrown vertically, the acceleration of it is the gravity acceleration independent if it is thrown downward or upward. However, the acceleration is a vector, so, when the ball is thrown upward, the movement is against the gravity, so the acceleration is negative, and so, the velocity decreases during time; and when the ball is thrown downward, the movement goes to the gravity, so the acceleration is positive, so the velocity increase after time passes.
The transfer of energy is potential energy to kinetic energy. The swing has potential energy when she pulls it back and once she lets go, allowing the swing to move, it then has kinetic energy.
Answer:
a. Decreases
b. Increases
c. Remains the same
d. Increases
Explanation:
a. Capacitance is given by c= Ak€/d
where A is conductivity plate with Area
K is a constant
€ is dielectric with permittivity.
d is the distance
b. Potential difference is given by
V = Ed, since, the electric field remains the
same, the potential diterence also increases with increase in distance.
Since the capacitance depends upon the distance, and all the other factors are kept constant, the capacitance decreases.
c. Electric field remains the same because charge on the
plate remains the same.
d. since electric field remains the same and capacitance decreases, the energy increases.
E= 1/2c * Q^2
