Lets do
We know
The rate of change of velocity is acceleration .


Integrate both sides

As acceleration is constant .Take it outside of integral .On velocity we can take limit u to v and time from 0 to t

Hence



If stars never changed, then constellations wouldn't change. But the stars, including the Sun, travel in their own separate orbits through the Milky Way galaxy. The stars move along with fantastic speeds, but they are so far away that it takes a long time for their motion to be visible to us.
Answer: a) angular acceleration(alpha)=-14.8rad/s^2
b) time taken (t) = 1.52s
Explanation:
What we are given
Mass of the solid sphere m =225g = 0.225kg
Diameter D = 3.00cm = 0.0300m
Radius = D/2 = 0.01500m
Frictional Force = 0.0200N
a) to determine the angular acceleration, we first calculate the torque, then moment of inertia, before the angular acceleration.
Torque = -fr
= - (0.0200)(0.01500)
=-3.00X10^-4Nm
Moment of inertia I
= 2/5mr^2
=2/5(0.225)(0.01500)^2
=2.025X10^-5kgm^2
Angular acceleration (alpha)= torque/moment of inertia (I)
= -3.00X10^-4Nm/2.025X10^-5kgm^2
=-14.8rad/s^2
b) time taken (∆t) = w/alpha
w= -22.5rad/s
Angular acceleration (alpha) = -14.8rad/s^2
∆t = -22.5/-14.8
= -1.52s
Answer
The second rock will land 2.4s after the first rock
Explanation:
Given that
Height of the building s=50m
We assume that the first rock is acting with gravity so that a=9.81m/s
And initial velocity u=0
Applying the equation of motion
S=ut+1/2at²
50=0*t+1/2(9.81)t²
50=4.905t²
t²=50/4.905
t²=10.19
t=√10.19
t=3.19sec
For the second rock initial velocity u=8m/s and v=0 and a=9.81
Applying the equation of motion
v=u+at
0=8+9.81t
t=-8/9.81
t=0.81sec
Hence the second rock will land 2.4s after the first rock
I.e
3.19-0.81
Then he fell in a sewer with lots of poop and you try to escape but a river of pee came rushing down and wash you away