The momentum of a moving object is given by:

where m is the mass of the object and v its speed.
In this problem, the ball has a mass of

and its momentum is

, so we can rearrange the previous equation to find the speed of the ball:
Answer:
D) the decay rates of radioactive uranium and lead
Explanation:
As we know that when she found the substance it must have some fixed ratio of radioactive uranium and Lead in that substance.
Here since Uranium is radioactive substance so it will continuously convert into Lead and this ratio will change with time
So here we can say that the ratio of radioactive uranium and lead will depend on its decay rate
now to find the age of the substance we can find the present ratio of lead and uranium in that substance and then compare it with freshly prepared substance.
so by the formula
we can find the age of the sample
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Answer:
25.2 cm
Explanation:
K = 1050 N/m
m = 1.95 kg
h = 1.75 m
By the conservation of energy, the potential energy of the block is converted into the potential energy stored in the spring
m g h = 1/2 x k x y^2
Where, y be the distance by which the spring is compressed.
1.95 x 9.8 x 1.75 = 1/2 x 1050 x y^2
33.44 = 525 x y^2
y = 0.252 m
y = 25.2 cm