One end of a string is attached to an object of mass M, and the other end of the string is secured so that the object is at rest as it hangs from the string. When the object is raised to a position X that is a height H above its lowest point and released from rest the object undergoes simple harmonic motion. When the object passes through the equilibrium position Y, it has a speed Which of the following methods could a student use to determine the total mechanical energy E at position Y, and why? A. E = Mug - MgH, because energy changes from kinetic energy to gravitational potential energy as the pendulum swings from position X to position Y
B. E=MgH - M y because energy changes from gravitational potential energy to kinetic energy as the pendulum swings from position X to position Y
C. E = Me, because this equation represents the maximum kinetic energy of the pendulum at position Y if the system has zero gravitational potential energy at position Y
D. E MgHube E = MgH, because this equation represents the maximum gravitational potential energy of the system at position X if the system has zero gravitational potential energy at position Y

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min

d is correct as long as you put the state each one it eg. (aq)

mg(no3)2(aq) + zn(s) > zn(2+)(aq) + ) + mg(s)

hope it !