1) Pushing on a car will not always change the car's mechanical energy, but it does change yours since your physically using most of your energy to push the car.
2) In order for a cars kinetic energy to increase, the car has to be in motion when it is going down a hill, because when you go down hills and objects like that; you tend to increase in kinetic energy.
Answer: A concave mirror focuses rays of light
Explanation:
Answer:
In parallel combination, the cells are connected in such a way that the potential difference of the circuit is same as the cells used in the circuit but the time of current flowing increases
Answer:
The magnitude of the magneticfield B[T] at a point on the surface of the earth directly below the power line is B=1.496x10^(-6) T.
Explanation:
The distance from the wire to a point in the surface is the heigth of the wire.
The formula for the magnetic field on any point at distance R from a wire conducting alternating current is:
Answer:
The resulting velocity of the ball after it hits the racket was of V= 51.6 m/s
Explanation:
m= 55.6 g = 0.0556 kg
t= 2.8 ms = 2.8 * 10⁻³ s
F= 1290 N/ms * t - 330 N/ms² * t²
F= 1024.8 N
F*t= m * V
V= F*t/m
V= 51.6 m/s
