Answer:
The total mechanical energy of a pendulum is conserved neglecting the friction.
Explanation:
- When a simple pendulum swings back and forth, it has some energy associated with its motion.
- The total energy of a simple pendulum in harmonic motion at any instant of time is equal to the sum of the potential and kinetic energy.
- The potential energy of the simple pendulum is given by P.E = mgh
- The kinetic energy of the simple pendulum is given by, K.E = 1/2mv²
- When the pendulum swings to one end, its velocity equals zero temporarily where the potential energy becomes maximum.
- When the pendulum reaches the vertical line, its velocity and kinetic energy become maximum.
- Hence, the total mechanical energy of a pendulum as it swings back and forth is conserved neglecting the resistance.
True because the neutrons are inside of the nucleus and the electron revolve around the nucleus
I think it's B ,go to physicsclassroom.com Newton's second law
Answer:C
Explanation:
When a constant horizontal force is applied to the box, box started moving in the horizontal direction such that it moves with constant velocity
Constant velocity implies that net force on the box is zero
i.e. there must be an opposing force which is equal to the applied force and friction force can serve that purpose.
So option c is the correct choice.
Answer: Rock require larger drag force and to achieve it rock need to move at a very high terminal velocity.
Explanation: Terminal velocity is defined as the final velocity attained by an object falling under the gravity. At this moment weight is balanced by the air resistance or drag force and body falls with zero acceleration i.e. with a constant velocity.
Case 1: Terminal velocity of a piece of tissue paper.
The weight of tissue paper is very less and it experiences an air resistance while falling downward under the effect of gravity.
Downward gravitational force, F = mg
Upward air resistance or friction or drag force will be
So, paper will attain terminal velocity when mg =
Case 2: Rock is very heavy and require larger air resistance to balance the weight of rock relative to the tissue paper case.
Downward force on rock, F = Mg
Drag force =
Rock will attain terminal velocity when Mg =
Mg > mg
so, >
And rock require larger drag force and to achieve it rock need to move at a very high terminal velocity.