Answer:
lowest level contains more energy
Explanation:
Answer:
The speed is maximum and the acceleration is zero
Explanation:
- The speed of the mass in simple harmonic motion can be found by using the law of conservation of energy. In fact, the total mechanical energy of the mass-spring system is sum of kinetic energy and elastic potential energy:

where
m is the mass
v is the speed
k is the spring constant
x is the displacement
As we can see, when the displacement is zero (x=0), the term representing the kinetic energy is maximum, so v (the speed) is also maximum.
- The acceleration of the mass in simple harmonic motion is proportional to the restoring force acting on the mass, which is given by Hook's law

where
k is the spring constant
x is the displacement
When x = 0, F = 0, so the net force acting on the mass is zero. Therefore, this also means that the acceleration of the mass is also zero: a = 0.
Answer:
The larger pebble has 25 times more mass.
Explanation:
To solve the exercise it is necessary to apply the work and energy conservation equations.
For the case described, the work done must be preserved and must be the same, that is,

By definition work linked to the conservation of kinetic energy would be given by






The ratio between the mass and the velocity would be,



Therefore the answer is: The larger pebble has 25 times more mass.
Answer:
Li has less mass and therefore less inertia, so he can change his motion more easily than Raj.
Explanation:
Inertia describes the resistance of an object to any change in its state of motion, and it depends on the mass of the object only. In particular:
- if an object has a large inertia (large mass), then it is more difficult to change its state of motion (i.e. to put it in motion, or to slow it down, or to change its direction of motion)
- if an object has small inertia (small mass), then it is more easy to change its state of motion
In this problem, Li has less mass than Raj, so he has less inertia, therefore he can change his motion more easily than Raj.
Answer:
A. 200 J
Explanation:
The initial kinetic energy depends on the initial speed, while the gravitational potential energy depends on the height, both balls are thrown with the same initial speed and from the same height. Therefore, due to the law of conservation of energy, the balls must have the same mechanical energy (the sum of both energies) when both impact the ground. Since the potential energy is zero at this point, its final kinetic energy must also be the same.