Solution :
Given :
M = 0.35 kg
Total mechanical energy = constant
or 
But 
and 
Therefore, potential energy at the top = kinetic energy at the bottom
(h = 35 cm = 0.35 m)
= 2.62 m/s
It is the velocity of M just before collision of 'm' at the bottom.
We know that in elastic collision velocity after collision is given by :
here, 
∴ 
= 0.33 m/s
Therefore, velocity after the collision of mass M = 0.33 m/s
Answer:
t = 2.13 10-10 s
, d = 6.39 cm
Explanation:
For this exercise we use the definition of refractive index
n = c / v
Where n is the refraction index, c the speed of light and v the speed in the material medium.
The refractive indices of ice and crown glass are 1.13 and 1.52, respectively, therefore the speed of the beam in the material medium is
v = c / n
As the beam strikes perpendicularly, the beam path is equal to the distance of the leaves, there is no refraction, so we can use the uniform motion relationships
v = d / t
t = d / v
t = d n / c
Let's look for the times on each sheet
Ice
t₁ = 1.4 10⁻² 1.31 / 3 10⁸
t₁ = 0.6113 10⁻¹⁰ s
Crown glass (BK7)
t₂ = 3.0 10⁻² 1.52 / 3.0 10⁸
t₂ = 1.52 10⁻¹⁰ s
Time is a scalar therefore it is additive
t = t₁ + t₂
t = (0.6113 + 1.52) 10⁻¹⁰
t = 2.13 10-10 s
The distance traveled by this time in a vacuum would be
d = c t
d = 3 10⁸ 2.13 10⁻¹⁰
d = 6.39 10⁻² m
d = 6.39 cm
Answer:
C.<u>ten</u><u> </u><u>times</u><u> </u><u>the</u><u> </u><u>intensity</u><u>.</u>
Angular acceleration = (change in angular speed) / (time for the change)
Change in angular speed = (speed at the end) - (speed at the beginning)
For this fan, speed at the end = 7700 rpm, speed at the end = 0 .
Change in angular speed = -7700 rpm
Angular acceleration = (-7700 rpm) / (2.5 sec)
<em>Angular acceleration = -3,080 rev per minute / sec</em>
That's a perfectly good and true answer to the question, but the units are ugly. We really need to fix the units, and convert them into something prettier before we hand in this assignment.
1 rev = 2π radians, and
1 minute = 60 seconds .
So
Angular acceleration =
(-3,080 rev/min-sec) · (2π rad/rev) · (1 min/60 sec)
AngAccel = (-3,080 · 2π · 1 / 60) · (rev·rad·min / min·sec·rev·sec)
AngAccel = ( -102 and 2/3 · π) · (rad/s²)
<em>AngAccel = -322.5 radian/s²</em>
The other 4 kg of mass may have departed the scene
of the fire, in the form of gases and smoke particles.
