REALLY NEED HELP, 3 QUESTIONS 20 POINTS. ONLY ANSWER IF YOU KNOW THE CORRECT ANSWER. DO NOT ANSWER WITH "I DON'T KNOW, SORRY" JUST FOR THE POINTS. Thanks very much, have a great day. ( I Will report you if you answer with "I don't know, sorry" 1) A spring with a natural height of 60 mm is compressed by a 300 g mass to a new height of 54 mm.
 Find the spring constant in SI units.
 Find the height of the spring if the 300 g mass were replaced by a 400 g mass

2) A spring is stretched by 2m with a force of 100 N. Calculate its spring constant.

3) You have just bought an innerspring mattress that contains coil springs in a rectangular array 20 coils wide and 40 coils long. You estimate that when you lie on the mattress, your weight is supported by about 200 springs (about one-fourth of the total number of springs in the mattress). You observe that the springs compress
about 2.0 cm when you lie on the mattress. Assuming that your weight of 600 N is supported equally by 200 springs, find the force constant of each spring.