A coin is mass 4.8kg and radius one meter rolling on a horizontal surf...
Motion of the Coin
The coin is rolling on a horizontal surface without sliding. This means that both translational motion (linear motion) and rotational motion are occurring simultaneously.
Given Information
- Mass of the coin: 4.8 kg
- Radius of the coin: 1 meter
- Angular velocity of the coin: 600 rotational min
Calculating Linear Velocity
To find the linear velocity of the coin, we can use the formula:
v = ω * r
where v is the linear velocity, ω (omega) is the angular velocity, and r is the radius of the coin.
In this case, the angular velocity is given in rotational min, so we need to convert it to radians per second.
1 rotational min = 2π radians
So, the angular velocity in radians per second is:
ω = (600 rotational min) * (2π radians / 1 rotational min) = 1200π radians per second
Now, substituting the values into the formula, we get:
v = (1200π radians per second) * (1 meter) = 1200π meters per second
Calculating Kinetic Energy
The total kinetic energy of the coin is the sum of its translational kinetic energy and rotational kinetic energy.
1. Translational Kinetic Energy:
The translational kinetic energy of an object can be calculated using the formula:
K_trans = (1/2) * m * v^2
where K_trans is the translational kinetic energy, m is the mass of the coin, and v is the linear velocity.
Substituting the values, we get:
K_trans = (1/2) * (4.8 kg) * (1200π meters per second)^2
2. Rotational Kinetic Energy:
The rotational kinetic energy of an object can be calculated using the formula:
K_rot = (1/2) * I * ω^2
where K_rot is the rotational kinetic energy, I is the moment of inertia, and ω is the angular velocity.
The moment of inertia for a solid sphere rolling without slipping is:
I = (2/5) * m * r^2
Substituting the values, we get:
I = (2/5) * (4.8 kg) * (1 meter)^2
Now, substituting the values into the formula, we get:
K_rot = (1/2) * [(2/5) * (4.8 kg) * (1 meter)^2] * [(1200π radians per second)^2]
Calculating the Total Kinetic Energy
To find the total kinetic energy, we simply add the translational and rotational kinetic energies together:
K_total = K_trans + K_rot
Finally, substituting the calculated values into the equation, we can find the total kinetic energy of the coin.
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