Newtons Laws of Motion

No, because the amount of force you have applied to the rock cancels with the reaction force from the rock pushing back. Action- reaction. Think about the different types of energy you need to consider:

½mv²

mgh

and possibly rotational ½iω²

Have you given the rock any of these things? If not then there has been no transfer of energy, save possibly the heat from your hands

Drag (air resistance). When a falling object reaches terminal velocity (continues to fall at a constant speed, but acceleration stops), the force of drag and the force of gravity are equal, but opposite in direction.

The answer to both of your questions lies in the different nature of both quantities, momentum and kinetic energy. Momentum is a vector, kinetic energy is a scalar. This means that momentum has a magnitude and a direction, while kinetic energy just has a magnitude. Consider the following system: 2 balls with equal mass are rolling with the same speed to each other. Magnitude of their velocities is the same, but the directions of their velocities are opposed. What can we say about the total momentum of this system of two balls? The total momentum is the sum of the momentum of each ball. Since masses are equal, magnitudes of velocities are equal, but direction of motion is opposed, the total momentum of the system of two balls equals zero. Conclusion: the system has zero momentum. What can we say about the total kinetic energy of this system? Since the kinetic energy does not take into account the direction of the motion, and since both balls are moving, the kinetic energy of the system will be different from zero and equals to the scalar sum of the kinetic energies of both balls. Conclusion: we have a system with zero momentum, but non-zero kinetic energy. Assume now that we lower the magnitude of the velocity of one of the balls, but keep the direction of motion. The result is that we lower the total kinetic energy of the system, since one of the balls has less kinetic energy than before. When we look to the total momentum of the new system, we observe that the system has gained netto momentum. The momentum of the first ball does not longer neutralize the momentum of the second ball, since the magnitudes of both velocities are not longer equal. Conclusion: the second system has less kinetic energy than the first, but has more momentum. If we go back from system 2 to system 1 we have an example of having more kinetic energy, but less momentum. I hope this answers your question Kjell

The invariant quantities such as angular momentum, linear momentum and possibly energy (although that is generally considered thermodynamics) are all still conserved in special relativity.

What does happen however is that the equations for these invariants do change. For example, linear momentum according to Newton is simply mass times velocity but in Einstein's theory it becomes mass times velocity times a new thing called the gamma factor (which is almost equal to unity at low velocities so Newton did not detect it, but becomes very large close to the speed of light (the gamma factor is infinite at the speed of light)).

Special relativity also predicts the existence of spin which is related to angular momentum, but spin does not exist in Newton's theory.

If the net forces on an object are balanced, the object will remain at rest or continue to move at a constant velocity. You can determine if forces are balanced by calculating the sum of the forces in each direction (e.g., horizontal and vertical) and comparing them. If the sum of the forces in each direction is zero, the forces are balanced.

The net downward force on an object is the total force acting on the object in the downward direction after considering all forces, such as gravity and any applied forces, acting on the object. It is calculated by summing up all the individual forces acting downwards on the object.

The rate of speed of action or occurrence is the frequency at which something happens or progresses over a specific unit of time. It measures how quickly a particular event or process unfolds.

Yes, if all the forces vector sum to zero then there is no acceleration. For example if a you push on sled with 10 pounds and someone else pulls the other end with 10 pounds it does not move - no acceleartaion - net force is zero even though two forces are acting on it

Forces are vector quantities. Draw a diagram with the forces on it in the correct direction. If both forces are acting in the same direction, ie South then add them.

12 N South. (Points of the compass take a capital /uppercase letter)

There is no such thing as "force of inertia". The passengers are thrown forward, maintaining their initial motion. This is an application of Newton's First Law, which states that an object in motion stays in motion unless acted upon a force. The force of the car brake is acted upon the car and not on the passengers. This is why the passengers continue to move forward for a second when the car stops.

While traveling on a wet road, a thin layer of water forms between the tyre and the road surface. This makes the car lose its traction and skid. Once the car loses traction it no longer responds to the steering or braking controls thus causing the car to skid. As the speed of the car increases, the affect of sliding also increases. This is due to the reduction in friction. Skidding also depends on the tire pressure, the amount of tire surface that is in contact with the road and so on. The affect is also known as hydroplaning or aquaplaning.

When car was moving, passengers were also moving. When car suddenly stops, the moving passengers try to maintain their state of forward motion because of their inertia. so they move forward relative to their seats...

If you suddenly let go of the rope, the brick will move in a direction tangent to the circle at that point. The only cause of circular motion is centripetal force which is tension of string or indirectly force of hand in this case. As soon as you vanish it, no circular motion is possible and projectile motion is performed.

This lack of sensation of motion is due to the absence of visual cues and the feeling of acceleration that our bodies are accustomed to on the ground to determine motion. When flying at a constant speed in smooth air, the absence of external visual references and changes in acceleration causes our brain to interpret the motion as still. Additionally, the gradual acceleration and deceleration during take-off and landing are typically when motion is more noticeable.

Yes, the ball is in equilibrium at its highest point because its acceleration is zero at that point. The forces acting on the ball (gravity and air resistance) are balanced, resulting in a net force of zero.

Before you let it go, the weight you feel in your hand is the force. After falling a long way, the increasing resistance due to the air finally balances the force. So there are now 2 forces, gravity + air resistance, with a total of zero. So there are forces, but they add up to nothing, and hence constant speed. When you hold it in your hand, the speed is also constant, zero, the force provided by you balances gravity. Acceleration is a sign of unbalanced force. Constant velocity is a sign of balanced force. This led to the idea by Monsieur d'Alembert, that in any situation involving forces and accelerations, in your Force Vector Diagram you can add a further component equal to the negative of (Mass x Acceleration) and then solve the problem as a problem of statics ("d'Alembert's Principle). Thus for a falling object in a vacuum (no air resistance) you have weight force F downwards, and mass times acceleration g UPwards, so as a "statics" problem, F=mg.

Momentum is a vector quantity, calculated as the product of an object's mass and velocity. Its SI unit is kilogram meters per second (kg m/s), which represents the combination of mass (kg) and velocity (m/s) in defining momentum. Momentum does not have a separate designated unit name because it is derived from fundamental SI units.

Placing wheels under a heavy box reduces the friction between the box and the surface it's resting on. This reduction in friction allows the box to move more smoothly, requiring less force to keep it moving at a constant speed. The wheels also help distribute the weight of the box more evenly, making it easier to overcome inertia and maintain momentum.

By Newton second law,

F=ma;

20=5*a;

or a=4m/s/s.

initial velocity=0

and time=10s

so by first equation of motion

V=0+at, so

V=4*10=40m/s,

so kinetic energy of body=K.E=1/2*m*V2 = 0.5*5*1600=25*160=.....

Newton's first law, also known as the law of inertia, states that an object at rest will stay at rest and an object in motion will stay in motion with a constant velocity unless acted upon by an external force. This law provides the foundation for understanding the concept of inertia, which is the tendency of an object to resist changes in its motion.

It isn't. It only feels more forceful because a fist would have a smaller contact area than a boxing glove. Being punched with a fist feels more forceful because the pressure (Force/Area) would be greater.

Imagine a force of 20 N. Imagine a fist with an area of .01 m2. Imagine a boxing glove of area .1 m2. The pressure of being hit with the fist would be 20N/.01m2 = 2000 Pa. The pressure of being hit with the boxing glove would be 20N/.1m2 = 200 Pa.

Note: These numbers do not represent real world numbers, necessarily. They are just guesses at what the components of pressure might be.

F=ma

a=F/m

a=7500/1500

a=5m/s^2

Not really, Newton's first law of motion is: "Every body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force. [2][3][4] This means that in the absence of a non-zeronet force, the center of mass of a body either remains at rest, or moves at a constant speed in a straight line."