Answer:
The angular velocity of Ball A will be greater than the angular velocity of Ball B when they reach the top of the hill.
Explanation:
Angular velocity can be defined as how fast an object rotates relative to a given point or frame of reference.
The question said the hill encountered by Ball A is frictionless, so Ball A will continue to rotate at the same rate it started with even when it reached the top of the hill.
Ball B on the other hand rolls without slipping over its hill, i.e there's friction to slow down its rotational motion which thus reduces how fast Ball B will rotate at the top of the hill
QUESTION:-A beam of white light shines onto a sheet of white paper. An identical beam of light shines onto a mirror. The light is scattered from the paper and reflected from the mirror.
Describe how scattering by paper and reflection by a mirror are different from each other.
ANSWER: Scattering sends or reflects light from each point on the object in all directions, whereas reflection sends light from each point on the object in one direction only (or to one point)
Answer:
Part(a): The angular acceleration is 
.
Part(b): The angular displacement is 
.
Explanation:
Part(a):
If 
be the initial angular speed, final angular speed and angular acceleration of the centrifuge respectively, then from rotational kinematic equation, we can write
where '
' is the time taken by the centrifuge to increase its angular speed.
Given, 
, 
and 
. From equation (
), the angular acceleration is given by
Part(b):
Also the angular displacement (
) can be written as
Answer:
the correct answer is E
A graph of the cart's maximum speed squared as a function of x^3
Explanation:
For this exercise let's use Newton's second law
F = m a
force has the form
F = k x²
and acceleration is related to velocity
a = dv / dt
Let's use the chain rule or L'Hospital
a = dv /dx dx/dt
a = dv /dx v
let's substitute
k x² = m v dv / dx
k /m x² dx = v dv
we integrate
k /m x³ /3 = v² / 2
v² = (2k /3m) x³
This is the expression for the variation of the speed as a function of the position, to make a linear graph realism the changes of variable
y = v²
x´ = x³
y = (2k/3m) x´
if we graph y vs x 'we have a linear graph whose slope is
m = 2k / 3m
By reviewing the different answers, the correct answer is E
Answer:
Explanation:
a) Change in momentum, Δp = mΔv = m(v - u) = (15 * 10-3) * (90 - 300) = -3.15 kg-m2
b) Acceleration of the bullet, a = (v2 - u2) / 2s = (902 - 3002) / (2 * 0.02) = -2047500 m/s2
So, the bullet is in contact with the plastic for the time, 
c) Average force, 
