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.
The rest energy of a particle is

where

is the rest mass of the particle and c is the speed of light.
The total energy of a relativistic particle is

where v is the speed of the particle.
We want the total energy of the particle to be twice its rest energy, so that

which means:


From which we find the ratio between the speed of the particle v and the speed of light c:

So, the particle should travel at 0.87c in order to have its total energy equal to twice its rest energy.
Answer:
Net Charge is -1.6 x 10 (to the negative 19th power) C. l
Explanation:
Service disconnect
this is the first disconnect device after the utility meter.
Answer:
1) v = 0.45 m/s
2) v = 0.65 m/s
3) v = 0.75 m/s
Explanation:
1) We can find the speed of the object by conservation of energy:


Where:
k: is the spring constant = 280 N/m
v: is the speed of the object =?
m: is the mass of the object = 5.00 kg
x: is the displacement of the spring

2) When the object is 5.00 cm (0.050 m) from equilibrium, the speed of the object is:
3) When the object is at the equilibrium position, the speed of the object is:

I hope it helps you!