Thanks Bob!
Also i found this useful site which gives step by step instructions:
https://www.disastersafety.org/earthquake/securing-flat-screen-televisions/
Securing Flat Screen Televisions
Securely mounting a television or computer monitor to the wall reduces the risk of injury and damage.
Before beginning work
The television should weigh less than 110 lbs and have a 60-inch diagonal screen size or smaller.
Check to make sure framing studs behind the drywall are not more than 24 inches on center apart.
If the tv weighs more than 110 lbs. or the studs are more than 24 inches on center, have the television professionally installed.
Materials List
Stud finder
Drill plus 1/8 inch, 1/4 inch and 3/8 inch diameter drill bits
3/4-inch thick x nominal 12-inch wide x 28-inch long (minimum) wood board (plywood or solid wood; NOT OSB or particle board)
Find additional guidance in the IBHS Guide, Earthquake Risks around the U.S. - How to Protect Your Property.
FOR WOOD STUD APPLICATIONS:
10 #14 or 1/4-inch diameter, 3-inch wood or deck screws
FOR METAL STUD APPLICATIONS:
14 1/4-inch diameter x 2-inch self-tapping screws intended for sheet metal applications (2) or (4) 5/16-inch diameter carriage bolts at least 1 inch (or longer depending on the thickness of the wall mount bracket) with flat washers and lock washers or lock nuts: the number of bolts depends on how many are required for the wall mount bracket.
Prep work
CUTTING THE WOOD
Cut the wood board used to mount the bracket to the wall, according to the requirements listed in Step 1. The board will be anchored to two adjacent studs.
The minimum nominal width of the wood board must be 12 inches (actual width 11-1/4" for a solid wood board)
Use a stud finder to locate two framing studs where the television is to be mounted.
Make sure the studs are no more than 24 inches apart.
Measure the existing television wall mount plate. The width of the wood board should be at least two inches greater than the vertical plate dimension. See illustration below.
Note: A metal detector may be required to find locations of metal studs in wall
PREPPING THE WOOD
Pre-drill holes in the wood board
Draw straight lines perpendicular to the long side of the board near each end of the wood board.
The distance between these two lines should equal the spacing between the center lines of two framing studs previous located in the wall.
Maintain a minimum 2-inch edge distance between each line and the edge of board.
Measure and locate wood screw installation holes along the two lines near each end of wood board as shown in the accompanying illustration.
Use the 1/4-inch drill bit to create holes in the board for the screws that are used to attach the board to the wall.
Position the television wall mount plate on the wood board at the desired location and outline the plate and locate the bolt holes.
Use the 3/8-inch drill bit to create the bolt holes for the 5/16-inch diameter carriage bolts to secure the wall mount assembly to the wood board.
PREPPING THE WALL
Locate the board on the wall
Position the wood board with pre-drilled holes described above vertically at the desired position.
The two lines near the ends of the board should be aligned with the centers of the two wall studs.
Mark locations where carriage bolt b. heads will come in contact with the drywall.
Mark the locations of the screws that will be used to fasten the board to the wall studs.
Pre-drill the holes on the wall and recess drywall to accommodate carriage bolt heads.
Use the 1/8-inch diameter drill bit to create holes for the screws along the two framing studs.
There should be more resistance to the drill when it hits the wood or metal stud behind the drywall.
All 10 holes [wood studs] or 14 holes [metal studs] must catch the framing stud behind the drywall, otherwise relocate the board.
Use a hard object with a small diameter to create a recess in drywall at the locations marked for the head of each carriage bolt.
Installation
Bolt the television wall mount plate to the wood board using the 5/16-inch diameter carriage bolts.
Use an appropriately sized flat washer next to the metal wall mount plate followed by the lock washer and nut or the lock nut.
After the wood board is secured to the wall, the television can be bolted onto the wall mount assembly following the manufacturer's recommendations.
© 2012 Insurance Institute for Business & Home Safety