Answer:
ac = 72 m/s²
Fc = 504 N
Explanation:
We can find the centripetal acceleration of the hammer by using the following formula:
where,
ac = centripetal acceleration = ?
v = constant speed = 12 m/s
r = radius = 2 m
Therefore,
<u>ac = 72 m/s²</u>
<u></u>
Now, the centripetal force applied by the athlete on the hammer will be:
<u>Fc = 504 N</u>
Answer:
Explanation:
Moment of inertia of a disc = 1/2 M R²
Since mass is same for both and radius are r and 2r, their moment of inertia can be in the ratio of 1: 4 . Let them be I and 4I . Angular speed are ω₀ and - ω₀ .
We shall apply law of conservation of angular momentum .
initial total angular momentum
I x ω₀ - 4I x ω₀ = - 3Iω₀
Let final common angular momentum be ω
total final angular momentum = ( I + 4I ) ω
Applying law of conservation of angular momentum
( I + 4I ) ω = - 3Iω₀
ω = - 3 / 5 ω₀ .
b )
Initial total rotational K E
= 1/2 I ω₀² + 1/2 4I ω₀²
= 1/2 x5I ω₀²
Final total rotational K E
= 1/2 ( I + 4I ) ( - 3 / 5 ω₀ )²
= 1/2 x 9 / 5 I ω₀²
= 9 / 10I ω₀²
change in rotational kinetic energy = 9 / 10I ω₀² - 1/2 x5I ω₀²
(9/10 - 5/2) xI ω₀²
=( .9 - 2.5 )I ω₀²
= - 1.6 I ω₀² Ans
Answer:
S = 122.5m
Explanation:
Given the following data;
Acceleration due to gravity = 9.8m/s²
Time, t = 5 seconds
Since it's a free fall, initial velocity, u = 0
To find the displacement, we would use the second equation of motion given by the formula;
Where;
- S represents the displacement or height measured in meters.
- u represents the initial velocity measured in meters per seconds.
- t represents the time measured in seconds.
- a represents acceleration measured in meters per seconds square.
Substituting into the equation, we have;
S = 122.5m.
The velcocity equals acceleration times time
which is 50 ms per sec