Which statement about the half-life of a radioactive sample is true?
O It is an exact measure of the decay of an individual atom.
O It measures the tendency of a radioisotope to decay radioactively
O It is affected by the concentration of the radioactive substance that is present
It can be calculated based on neutron number

How much force must a locomotive exert on a 12840-kg boxcar to make it accelerate forward at 0.490 m/s2?

The temperature in gavin's oven is a sinusoidal function of time. gavin sets his oven so that it has a maximum temperature of 280°f and a minimum temperature of 240°. once the temperature hits 280°, it takes 20 minutes before it is 280° again. gavin's cake needs to be in the oven for 30 minutes at temperatures at or above 270°. he puts the cake into the oven when it is at 260° and rising. how long will gavin need to leave the cake in the oven? (round your answer to the nearest minute.)

Discuss the difference between thermal energy and heat. (terrance) terrance, egolf, r., congdon, donald. physical science student text, 5th edition. bju press, 2014. vitalbook file.