Answer:
T = 570 N
Explanation:
Given that,
The gravitational force acting on a bucket of water = 525 N
Net force in the Y direction is 45 N
We need to find the magnitude of the force of tension. It can be calculated as :
45 = T - 525
T = 525 + 45
T = 570 N
Hence, the force of tension is 570 N.
1) 
When both the electric field and the magnetic field are acting on the electron normal to the beam and normal to each other, the electric force and the magnetic force on the electron have opposite directions: in order to produce no deflection on the electron beam, the two forces must be equal in magnitude

where
q is the electron charge
E is the magnitude of the electric field
v is the electron speed
B is the magnitude of the magnetic field
Solving the formula for v, we find

2) 4.1 mm
When the electric field is removed, only the magnetic force acts on the electron, providing the centripetal force that keeps the electron in a circular path:

where m is the mass of the electron and r is the radius of the trajectory. Solving the formula for r, we find

3) 
The speed of the electron in the circular trajectory is equal to the ratio between the circumference of the orbit,
, and the period, T:

Solving the equation for T and using the results found in 1) and 2), we find the period of the orbit:

In collision type of problems since momentum is always conserved
we can say

So here along with this equation we also required one more equation for the restitution coefficient

so above two equations are required to find the velocity after collision
here the change in velocity occurs due to the contact force while they contact in each other
so this is the impulse of collision while they are in contact with each other while in collision which changes the velocity of two colliding objects
Period of a simple pendulum = 2π √(L/G)
(25 sec/15) = 2π √(L / 9.8 m/s²)
5/3 sec = 2π √(L/9.8 m/s²)
5 sec / 6π = √ (L/9.8 m/s²)
(5sec · √9.8m/s²) / 6π = √L
Square each side:
(25 s²) · (9.8 m/s²) / 36π² = L
L = (25 · 9.8) / (36 π²) meters
L = 0.69 meter