a plasma is a hot ionized gas consisting of equal numbers and positively charged ions and negativly charged electrons. the characterisitcs of plasma are different from those of oirdinary gases so plama is consideres the fourth state of matter
Probably to be more accurate. With hand-operated stop watches there is more room for (human) error.
Option c. are large
Igneous rocks are crystalline solids which are formed after the magma cools. The sizes vary greatly depending on how quickly the magma cooled. The slower the cooling, the larger the crystals in the final rock. They cooled at depth in the crust where they were insulated by layers of rock and sediment.
Answers:
a) 
b) 
c) 
Explanation:
We have the following data:
is the spring constant
is the amplitude of oscillation
is the velocity of the block when
Now let's begin with the answers:
<h3>a) Mass of the block</h3>
We can solve this by the conservation of energy principle:
(1)
Where:
is the initial potential energy
is the initial kinetic energy
is the final potential energy
is the final kinetic energy
Then:
(2)
Isolating
:
(3)
(4)
(5)
<h3>b) Period</h3>
The period
is given by:
(6)
Substituting (5) in (6):
(7)
(8)
<h3>c) Maximum acceleration</h3>
The maximum acceleration
is when the force is maximum
, as well :
(9)
Being 
Hence:
(10)
Finding
:
(11)
(12)
Finally:
