Answer:
0.0000076 grams
Explanation:
We're given the half life of Tritium to be 12.3 years. In order to find out the amount of substabce remaining:
Let's first find how many 'half lives' are in 250 years.

Now what is half life? It means the time taken for a given quantity of an element to lose half it's mass.
So in 12.3 years we can find that The amount of 250 g of Tritium will be 250/2 = 125 g. In 24.6 years we'll have 125/2 = 62.5 g
So now we can devise a formula:

Where m is the remaining amount and n is th number of half lives in the time given.
Using this formula we can calculate:

Doing this calculation we get:

As we can see a very small value remains.
Answer:

Explanation:
Given:
The area of the house 
The height of the house 
We need to find the volume of a typical house.
Solution:
We find the volume of the house by multiplying the area of the house and height of the house.


Area and height of the house are known, so we substitute these value in above equation.


Now we convert the unit from feet to meter.
Divide the volume by 3.2808 for 


Therefore, the volume of the house is 
Answer:
A circular pizza has a angle of 360 degrees. When you cut it into 3 equal pieces you divide 360 by 3,you get 120 degrees. And following the conversion of 120 degree into radian you get 2pie/3 radians.
Answer:
the current flowing in each is the same.
Explanation:
When resistors are connected in series, they are connected in the same branch of the circuit - this means that the same current flows through each resistor.
The other options listed are wrong because:
the same power is dissipated in each one --> false: the power dissipated in each resistor is
, where I is the current and R the resistance, so it depends on the value of the resistance
the potential difference across each is the same.-- > false: this is true in parallel circuits, not series circuits
the equivalent resistance of the circuit is less than that of the smallest resistor.--> false: the equivalent resistance of a series circuit is the sum of the individual resistances:
, so it is larger than the resistance of the smallest resistance
the equivalent resistance of the circuit is equal to the average of all the resistances. --> false: the equivalent resistance of a series circuit is the sum of the individual resistances:
, not the average
Answer:
Given: a projectile of initial launch velocity(V) and launch angle ∅ and no air resistance. At the maximum height, the projectile would have a zero contribution of speed from the vertical component(Vy) Therefore, if we say Vx=Vcos∅ is the only speed the projectile has at the instant of maximum height then we can replace Vx with 1/5V and write 1/5V=Vcos∅. Solving for the the launch angle ∅, gives Inverse Cos(1/5)=78.5 degrees.