Is the force of friction the sum of all the microscopic contact forces between the bottom of the block and the surface?
1 answer:
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Answer:
The length at the final temperature is 11.7 cm.
Explanation:
We need to use the thermal expansion equation:
Where:
- L(0) is the initial length
- ΔT is the differential temperature, final temperature minus initial temperature (T(f)-T(0))
- ΔL is the final length minus the initial length (L(f)-L(0))
- α is the coefficient of linear expantion of steel (12.5*10⁻⁶ 1/°C)
So, we have:
Therefore, the length at the final temperature is 11.7 cm.
I hope it helps you!
When the ball starts its motion from the ground, its potential energy is zero, so all its mechanical energy is kinetic energy of the motion:
where m is the ball's mass and v its initial velocity, 20 m/s.
When the ball reaches its maximum height, h, its velocity is zero, so its mechanical energy is just gravitational potential energy:
for the law of conservation of energy, the initial mechanical energy must be equal to the final mechanical energy, so we have
From which we find the maximum height of the ball:
Therefore, the answer is yes, the ball will reach the top of the tree.
where m is the ball's mass and v its initial velocity, 20 m/s.
When the ball reaches its maximum height, h, its velocity is zero, so its mechanical energy is just gravitational potential energy:
for the law of conservation of energy, the initial mechanical energy must be equal to the final mechanical energy, so we have
From which we find the maximum height of the ball:
Therefore, the answer is yes, the ball will reach the top of the tree.