The answer is above but I don't know if it's correct.
Answer:
T = 6.0 N
Explanation:
given,
mass of the cord = 0.46 Kg
length of the supports = 7.2 m
time taken to travel = 0.74 s
tension in the chord = ?
using formula for tension calculation



v = 9.73 m/s
now, calculation of tension

T = 6.0 N
The tension in the cord is equal to 6.0 N.
Answer:
The magnetic field along x axis is

The magnetic field along y axis is zero.
The magnetic field along z axis is

Explanation:
Given that,
Length of the current element 
Current in y direction = 5.40 A
Point P located at 
The distance is


We need to calculate the magnetic field
Using Biot-savart law

Put the value into the formula

We need to calculate the value of 



Put the value into the formula of magnetic field


Hence, The magnetic field along x axis is

The magnetic field along y axis is zero.
The magnetic field along z axis is

Explanation:
0.566kg *(1mol/0.197 kg)= 2.87 mol gold
note how the units cancel out, if the units do not cancel out (kg/kg=1) then u did something wrong