To expand from FP's advice, if your hood struts are working, once you pass 45degrees, you should be able to feel the spring action forcing the hood up to the first locked position (about 60degrees thereabouts). Pressing a button near the middle of the strut allows you to further push up the hood to the second (and final) locked position which is almost perpendicular to the ground.

If you need to keep holding onto the hood even up to 45degrees, then you might need to replace your hood strut. Or have someone hold it up for you