In: Physics
The position of a particle moving along the x axis depends on the time according to the equation x = ct2 - bt3, where x is in meters and t in seconds.
For the following, let the numerical values of a and b be 3.7 and 1.0 respectively.
a) At what time does the particle reach its maximum positive x position?
b) What distance does the particle cover in the first 4.0s?
c) What is its displacement from t=0s to t-4.0s?
d) What is its velocity at t = 1.0?
What is its velocity at t = 2.0?
What is its velocity at t = 3.0?
What is its velocity at t = 4.0 s?
e) What is its acceleration at t = 1.0 s?
m/s2
What is its acceleration at t = 2.0 s?
m/s2
What is its acceleration at t = 3.0 s?
m/s2
What is its acceleration at t = 4.0 s?
m/s2
The position of particel as a function of time is given by
x=3.7t2-t3
a) for x to be maximum, dx/dt=0
dx/dt = 7.4t-3t2 = 0
t=0 or t= 2.467 second
x(0)=3.7*02-03=0 and x(2.467)=3.7*2.4672-2.4673=7.5 m
x reached its maximum positive value at 2.467 seconds
b) distnace travelled by particle in time 0 to 4 seconds is given by
because distnace is always positive.
between 0 and 2.467m, the velocity is positive and beyond 2.467 m, the velocity is negative
distnace travelled =
c) displacement is given by
Displacement = -4.8 m
d) velocity = dx/dt = 7.4t-3t2
velocity at t=1 = 7.4*1-3*12 = 4.4 m/s
velocity at t=2 = 7.4*2-3*22 = 2.8 m/s
velocity at t=3 = 7.4*3-3*32 = -4.8 m/s
velocity at t=4 = 7.4*4-3*42 = -18.4 m/s
e) acceleration = dv/dt = 7.4-6t
acceleration at t=1 = 7.4-6*1=1.4 m/s2
acceleration at t=2 = 7.4-6*2=-4.6 m/s2
acceleration at t=3 = 7.4-6*3=-10.6 m/s2
acceleration at t=4 = 7.4-6*4=-16.6 m/s2