The period of the pendulum doesn't determine the length of the string.
It's the other way around.
The period of the pendulum is proportional to the square root of its length.
So if you want to triple the period, you have to make the string nine times
as long as it is now.
Explanation :
The forces acting on hot- air balloon are:
Weight, (W)
Force due to air resistance, (F)
Upthrust force, (U)
Its weight W is acting in downward direction. The upthrust force U acts in upward direction. When the balloon is moving upward, the air resistance is in downward and vice versa.
In this case, the hot-air balloon descends vertically at constant speed.
so, 
and 
so, 
....................(1)
when it is ascending let the weight that it is releasing is R, so
..........(2)
solving equation (1) and (2)
2F is the weight of material that must be released from the balloon so that it ascends vertically at the same constant speed.
Blue light will bend more than the others because it has a slightly greater refractive index. This is because blue light has a shorter wavelength and more energy, meaning it has to slow down more than the others when it hits the water.
F - False.
The law of conservation of momentum states that the total momentum is conserved.
It would be B
Explanation:
Because if you're not measuring in inches you want to go the next one down other than inches which would be millimeters!(: hope this helps.
