Answer:

0.3619sec
Explanation:
Given that
Mass,m=148 g
Length,L=13 cm
Velocity,u'(0)=10 cm/s
We have to find the position u of the mass at any time t
We know that

Where 

u(0)=0
Substitute the value

Substitute u'(0)=10


Substitute the values

Period =T = 2π/8.68
After half period
π/8.68 it returns to equilibruim
π/8.68 = 0.3619sec
Answer:
<em>Choice: c. 6sec</em>
Explanation:
<u>Horizontal Launch
</u>
When an object is thrown horizontally with a speed (v) from a height (h), it describes a curved path ruled by gravity until it finally hits the ground.
The horizontal component of the velocity is always constant because no acceleration exists in that direction, thus:

The vertical component of the velocity changes in time because gravity makes the object fall at increasing speed given by:

Where 
To calculate the time the object takes to hit the ground, we use the same formula as for free-fall, since the time does not depend on the initial speed:

The marble rolls the edge of the table at a height of h=180 m, thus:


t = 6 sec
Choice: c. 6sec
Answer:
It would take two half-lives which would be 130days
The substance has a half-life of 30 minutes. There has been two cycles that have occurred.
idk the last one
Explanation: