This question involves the concepts of the law of conservation of energy and kinetic energy.
The girl's fastest speed is "3.7 m/s".
According to the law of conservation of energy, the girl will have the fastest speed at mean position, which will be calculated as follows:
Loss in Potential Energy = Gain in Kinetic Energy
where,
v = maximum speed = ?
g = acceleration due to gravity = 9.81 m/s²
Δh = change in height = 1.3 m - 0.6 m = 0.7 m
Therefore,
<u>v = 3.7 m/s</u>
<u></u>
Learn more about the Law of Conservation of Energy here:
brainly.com/question/381281?referrer=searchResults
Answer:
f1 = -3.50 m
Explanation:
For a nearsighted person an object at infinity must be made to appear to be at his far point which is 3.50 m away. The image of an object at infinity must be formed on the same side of the lens as the object.
∴ v = -3.5 m
Using mirror formula,
i/f1 = 1/v + 1/u
Where f1 = focal length of the contact lens, v = image distance = -3.5 m, u = object distance = at infinity(∞) = 1/0
∴ 1/f1 = (1/-3.5) + 1/infinity
Note that, 1/infinity = 1/(1/0) = 0/1 =0.
∴ 1/f1 = 1/(-3.5) + 0
1/f1 = 1/(-3.5)
Solving the equation by finding the inverse of both side of the equation.
∴ f1 = -3.50 m
Therefore a converging lens of focal length f1 = -3.50 m
would be needed by the person to see an object at infinity clearly
<u>Mass</u>
- Mass is measured in kilograms.
- Mass does not change when gravity changes.
- Mass is the amount of matter in something.
<u>Weight</u>
- Before I answer, we have to know weight formula. Weight = mass × acceleration due to gravity.
- Therefore, weight is measured in Newtons.
- Weight changes when gravity changes. This is because weight is dependent on acceleration due to gravity.
- Weight is a gravitational force.
Hope you could understand.
If you have any query, feel free to ask.
Answer:
va = 4.79 m/s
vb = 1.29 m/s
Explanation:
Momentum is conserved:
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(3.00) (0) + (6.50) (3.50) = (3.00) v₁ + (6.50) v₂
22.75 = 3v₁ + 6.5v₂
For an elastic collision, kinetic energy is conserved.
½ m₁u₁² + ½ m₂u₂² = ½ m₁v₁² + ½ m₂v₂²
m₁u₁² + m₂u₂² = m₁v₁² + m₂v₂²
(3.00) (0)² + (6.50) (3.50)² = (3.00) v₁² + (6.50) v₂²
79.625 = 3v₁² + 6.5v₂²
Two equations, two variables. Solve with substitution:
22.75 = 3v₁ + 6.5v₂
22.75 − 3v₁ = 6.5v₂
v₂ = (22.75 − 3v₁) / 6.5
79.625 = 3v₁² + 6.5v₂²
79.625 = 3v₁² + 6.5 ((22.75 − 3v₁) / 6.5)²
79.625 = 3v₁² + (22.75 − 3v₁)² / 6.5
517.5625 = 19.5v₁² + (22.75 − 3v₁)²
517.5625 = 19.5v₁² + 517.5625 − 136.5v₁ + 9v₁²
0 = 28.5v₁² − 136.5v₁
0 = v₁ (28.5v₁ − 136.5)
v₁ = 0 or 4.79
We know v₁ isn't 0, so v₁ = 4.79 m/s.
Solving for v₂:
v₂ = (22.75 − 3v₁) / 6.5
v₂ = 1.29 m/s
