tealdonkey776

A 765 g sample of polonium-210 (which has a half life of 138 days) is stored for 3.8 years. Determine how much polonium-210 remains.

How long is required for 75 atoms of lead-212 (which has a half life of 10.6 hours) to be reduced to only 9 atoms of lead -212?

A boat oscillates up-and-down on the water with a frequency of 0.25Hz. How long does it take for the boat to make 5 complete oscillations?

Sophie is trying to measure the speed of sound. She stands 24.0 m away from the wall and claps repeatedly, changing the frequency until the echo synchronised with her claps. If she calculates the speed of sound as 325 ms^-1 how long did she wait between collapse?