Answer:
Kinetic energy is 1425.11 J.
Explanation:
Given:
Mass of the wrench is, 
Height of fall is, 
Force of resistance is, 
Now, the total energy at the top is equal to the potential energy of the wrench at the top since the kinetic energy at the top is 0.
Now, potential energy at the top is given as:

Now, the potential energy at the top is converted to kinetic energy at the bottom and some energy is wasted in overcoming the resistance force by air.
Potential Energy = Kinetic energy + Energy to overcome resistance.
⇒ Kinetic energy = Potential Energy - Energy to overcome resistance.
Energy to overcome resistance force is the work done by the wrench against the resistance force and is given as:

Therefore, Kinetic energy at the bottom is given as:

Hence, the kinetic energy of the wrench be when it hits the water is 1425.11 J.
Answer:
Newton's second law of motion states that the acceleration of a system is directly proportional to and in the same direction as the net external force acting on the system, and inversely proportional to its mass. In equation form, Newton's second law of motion is a=Fnetm a = F net m .
Explanation:
Answer:
D) momentum of cannon + momentum of projectile= 0
Explanation:
The law of conservation of momentum states that the total momentum of an isolated system is constant.
In this case, the system cannon+projectile can be considered as isolated, because no external forces act on it (in fact, the surface is frictionless, so there is no friction acting on the cannon). Therefore, the total momentum of the two objects (cannon+projectile) must be equal before and after the firing:

But the initial momentum is zero, because at the beginning both the cannon and the projectile are at rest:

So the final momentum, which is sum of the momentum of the cannon and of the projectile, must also be zero:

Answer:
The time it takes for 14C to radioactively decay is described by its half-life. C has a half-life of 5,730 years. In other words, after 5,730 years, only half of the original amount of 14C remains in a sample of organic material. After an additional 5,730 years–or 11,460 years total–only a quarter of the 14C remains.
Explanation:
Hope this helps