math
posted by John .
When a person is swinging the amplitude (the swings"s distance above it's rest position) increases with each pump. According to Scientific magazine the amplitude increases by adding a constant when the person pumps sitting down, and by multiplying by a constant when the person pumps standing up. Suppose that when you get on a swing, its amplitude is 3cm (ie t(sub 0) =3). Assume that the amplitude increases by 2 cm each pump when you are sitting, and increases by multiplying by 1.2 each pump when you are standing.
a. what is your amplitude after 20 pumps if you are standing? If you are sitting?
b. What is the minimum number of pumps needed to make the amplitude equal 75 cm when you pump sitting down? Standing up?

sitting: a = 3+2p for p pumps
standing: a = 3*1.2^p for p pumps
3+2(20) = 43
3*1.2^20 = 115
3+2p = 75: p=36
3*1.2^p = 75: p=18
Respond to this Question
Similar Questions

physics
A person bounces up and down on a trampoline, while always staying in contact with it. The motion is simple harmonic motion, and it takes 2.82 s to complete one cycle. The height of each bounce above the equilibrium position is 40.8 … 
econ
If a person's nominal income increases by 8% while the price level increases by 10%, the person's real income: a) increases by 2%, b) increases by 18%, c) decreases by 18%, d) decreases by 2%. 
Science
Does intensity increase as amplitude increases? 
Physics waves check answers please
1. A vibrating point on a spring travels 60 mm during three cycles. What is the amplitude of the vibration? 
Physics waves check answers please
1. A vibrating point on a spring travels 60 mm during three cycles. What is the amplitude of the vibration? 
Physics waves check answers please
1. A vibrating point on a spring travels 60 mm during three cycles. What is the amplitude of the vibration? 
Precalculus
An object is attached to a coiled spring. The object is pulled down (negative direction from the rest position) 88 centimeters, and then released. Write an equation for the distance d of the object from its rest … 
precalc
An object is attached to a coiled spring. The object is pulled down (from its rest position) and then released. Given that the distance from its rest position at time t = 0 is 3 inches, its amplitude is 3 inches, and its period is … 
math
A spring is stretched 5 inches abobe its rest position. Itis then released and oscillates in damped harmontic motin with a frequency of 2cycles per second. After 7 seconds you measure the amplitude of the spring to be 1.5cm. 1.Find … 
Algebra
When a person is swinging the amplitude (the swings"s distance above it's rest position) increases with each pump. According to Scientific magazine the amplitude increases by adding a constant when the person pumps sitting down, and …