<span>1.0x10^3 Joules
The kinetic energy a body has is expressed as the equation
E = 0.5 M V^2
where
E = Energy
M = Mass
V = Velocity
Since the shot was at rest, the initial energy is 0. Let's calculate the energy that the shot has while in motion
E = 0.5 * 7.2 kg * (17 m/s)^2
E = 3.6 kg * 289 m^2/s^2
E = 1040.4 kg*m^2/s^2
E = 1040.4 J
So the work performed on the shot was 1040.4 Joules. Rounding the result to 2 significant figures gives 1.0x10^3 Joules</span>
Angular frequency in radian per second for 20 vibrations in 10 seconds is 12.6 rad/s
<h3>What is Angular frequency?</h3>
Angular frequency is the number of vibrations in radian per second.
The total number of vibrations n is 20 and the time taken for these vibrations is 10 s
The frequency of the vibrations will be
f = 20 / 10 = 2 Hz
Angular frequency is related to the frequency as
ω = 2πf
ω=2π × 2
ω = 12.6 rad/s
Thus, the angular frequency is 12.6 rad/s.
Learn more about Angular frequency.
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Answer:
a) Revolutions per minute = 2.33
b) Centripetal acceleration = 11649.44 m/s²
Explanation:
a) Angular velocity is the ratio of linear velocity and radius.
Here linear velocity = 72 m/s
Radius, r = 0.89 x 0. 5 = 0.445 m
Angular velocity

Frequency

Revolutions per minute = 2.33
b) Centripetal acceleration

Here linear velocity = 72 m/s
Radius, r = 0.445 m
Substituting

Centripetal acceleration = 11649.44m/s²
<h2>The option ( c ) is correct</h2>
Explanation:
When we apply the force on any body , the inertia comes into play . It is the tenancy of the the body to oppose the force which tends to change its state .
In first case the train tries to change its state from rest to motion . Thus the inertia of rest opposes this tendency.
In the second case , the train tries to come from motion to the state of rest . Thus again , inertia opposes it .
Therefore inertia is the factor which creates difficulty in both case . Hence option ( c ) is correct