Answer:
V=203 ft/s
Explanation:
answer is available in word document named "attach 1" due to some technical error in maths equation. please find the attached document
Answer:
in order to find the average velocity use change in Displacement / change in time?
Explanation:
Answer:

Explanation:
Generally from kinematics equations we have that
Here u is the initial velocity of the rock and the value is 0 m/s given that there was no information that it was in motion before the fall
substituting 1.43 s for t and
for g we have that
=> 
The negative sign show that the displacement is in the direction of the negative y-axis
Answer:
x(t)=0.337sin((5.929t)
Explanation:
A frictionless spring with a 3-kg mass can be held stretched 1.6 meters beyond its natural length by a force of 90 newtons. If the spring begins at its equilibrium position, but a push gives it an initial velocity of 2 m/sec, find the position of the mass after t seconds.
Solution. Let x(t) denote the position of the mass at time t. Then x satisfies the differential equation
Definition of parameters
m=mass 3kg
k=force constant
e=extension ,m
ω =angular frequency
k=90/1.6=56.25N/m
ω^2=k/m= 56.25/1.6
ω^2=35.15625
ω=5.929
General solution will be
differentiating x(t)
dx(t)=-5.929c1sin(5.929t)+5.929c2cos(5.929t)
when x(0)=0, gives c1=0
dx(t0)=2m/s gives c2=0.337
Therefore, the position of the mass after t seconds is
x(t)=0.337sin((5.929t)