A body of 2.0kg mass makes an elastic collision with another at rest and continues to move in the original direction but with 1/4 of it's original speed. what is the mass of the struck body?

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

Will give brainliest! which statement best describes the difference between strong nuclear forces and weak nuclear forces? weak nuclear forces are involved when certain types of atoms break down. strong nuclear forces are responsible for holding atoms' nucleus together. weak nuclear forces hold bonds between atoms together. strong nuclear forces hold together the nucleus of an atom. strong nuclear bonds prevent atoms from falling apart. weak nuclear bonds prevent compounds from falling apart. strong nuclear forces are involved in breaking electrons from their shells. weak nuclear forces hold protons in the nucleus.

Can anybody me with this? ? (picture included.)