During this time, the total mechanical energy of the object remains constant.
Answer: Option C
<u>Explanation:</u>
The sum total of potential energy and the kinetic energy presented in the system is called mechanical energy. The total mechanical energy in the system, which represents the combined potential and kinetic energies, remains constant as long as the only force work at conservative forces, and mechanical energy is maintained on this principle.
For example, a gravity box in which we throw the ball straights up, and then leave the hand with a specific amounts of kinetic energy. In the first half of the track, there is no kinetic energy, but it has potential energy similar to kinetic energy that it had when that left our hand. When we catch that again, it has the same kinetic energy as when that left our hand. That is why gravity belongs to the category of conservative forces.
Answer:
A) Air resistance acts in a direction opposite the the fall of an object reducing it by doing work against the weight of the object due to gravity.
B) using a ping pong ball, the time of fall will be greatly reduced since it has little weight (its mass x acceleration due to gravity) against the air resistance. The net downward force of the weight and the air resistance will be small.
C) No, I wouldn't expect them to fall at the same time. The steel ball will have more weight compared to the ping pong ball and hence it will have a larger net force downwards.
D) If they are both released from a 6 m height, the steel ball will fall to the ground first since it has a larger net force downwards.
Answer: I dont see the option choices
Explanation:
Answer:
0.8 N
Explanation:
From coulomb's law,
Formula:
F = kqq'/r²........................ Equation 1
Where F = Force of repulsion, k = coulomb's constant, q = first positive charge, q' = second positive charge, r = distance between the charge.
Given: q = 20 μC = 20×10⁻⁶ C, q' = 100 μC = 100×10⁻⁶ C, r = 150 cm = 1.5 m.
Constant: k = 9×10⁹ Nm²/C²
Substitute these values into equation 1
F = (20×10⁻⁶ )( 100×10⁻⁶)(9×10⁹)/1.5²
F = 1800×10⁻³/2.25
F = 1.8/2.25
F = 0.8 N
Blue light can knock electrons off a plate, but red light can't
