1 con lắc lò xo có khối lượng m, độ cứng K= 45N/m. Cho con lắc dao động điều hòa với biên độ A=20cm thì a cực đại =18m/s2. Xác định khối lượng m

tube or goog will be great resources to find the answer to the question that you're asking

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).