A car accelerates from 30 ft/s to 90 ft/ sec in 6 seconds
1 answer:
You might be interested in
The kinetic energy of an object of mass m and velocity v is given by
Let's call
the initial speed of the car, so that its initial kinetic energy is
where m is the mass of the car.
The problem says that the car speeds up until its velocity is twice the original one, so
and by using the new velocity we can calculate the final kinetic energy of the car
so, if the velocity of the car is doubled, the new kinetic energy is 4 times the initial kinetic energy.
Let's call
where m is the mass of the car.
The problem says that the car speeds up until its velocity is twice the original one, so
and by using the new velocity we can calculate the final kinetic energy of the car
so, if the velocity of the car is doubled, the new kinetic energy is 4 times the initial kinetic energy.
It will take 267 milliseconds for a sample of radon-218 to decay from 99 grams to 0. 50 grams.
We know that half life of a first order reaction is given by:
where k = rate of reaction
Given half life = 35 milliseconds
So from this we get k = 0.0198
Now we know that rate of first order reaction is given by:
where t= time
R'= initial amount = 99 g
R= final amount= 0.50 g
k= rate of reaction = 0.0198
Putting values of these in above equation we get t=267 milliseconds.
i.e. It will take 267 milliseconds for a sample of radon-218 to decay from 99 grams to 0. 50 grams.
To know more about radioactivity visit:
#SPJ4