I've just discovered a new radioactive element. at 1: 00 pm i measure 10 grams of the element, but at 1: 24 pm i measure only 1.25 grams of the element (with 8.75 grams of daughter product). how long is each half life, in minutes? (just enter the number).

Each half life is 8 minutes long.

Explanation:

Expression for rate law for first order kinetics is given by:

where,

k = rate constant  

t = age of sample  = 24 minutes

a = initial amount of the reactant  = 10 grams

a - x = amount left after decay process  = 1.25 grams

for completion of half life:  

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Thus half life is 8 minutes long

the area between the graph and the t axis

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.