Centripetal force is equal to (mv^2)/r
The way I use to answer these question is to set every variable to 1
m=1
v=1
r=1
so centripetal force =1
then change the variable we're looking at
and since we're find when it's half we could either change it to 1/2 or 2, but 2 is easier to use
m=1
v=2
r=1
((1)×(2)^2)/1=4
So the velocity in the 1st part is half the velocity in the 2nd part and the centripetal force is 4× less
The answer is the centripetal force is 1/4 as big the second time around
Answer:

Explanation:
The momentum change is defined as:

Taking the downward motion as negative and the upward motion as positive, we have:

Replacing (2) and (3) in (1):

-- Equations #2 and #6 are both the same equation,
and are both correct.
-- If you divide each side by 'wavelength', you get Equation #4,
which is also correct.
-- If you divide each side by 'frequency', you get Equation #3,
which is also correct.
With some work, you can rearrange this one and use it to calculate
frequency.
Summary:
-- Equations #2, #3, #4, and #6 are all correct statements,
and can be used to find frequency.
-- Equations #1 and #5 are incorrect statements.
ANSWER:
3408.81 kg
STEP-BY-STEP EXPLANATION:
Given:
v = 111 m/s
Ek = 21000000 J
We have that the formula for kinetic energy is as follows:

We substitute the values given in the exercise and solve for m (mass)

The mass of the helicopter is 3408.81 kilograms.
<span>The question is asking us to fill in the gap in: (gap) is a force of attraction that occurs between objects due to their mass.The correct answer is b. gravity. People don't know that gravity works both ways: both objects atract each. The reason why we're more attracted to Earth than Earth is pulled to us is that Earth has a much higher mass - the bigger the mass, the stronger the atraction</span>