Answer:
P = mgh/t = 61(9.8)(0.32)/1.8 = 106.275555... ≈ 110 W
Explanation:
Power is the rate of doing work.
The work changes her potential energy.
Explanation:
Given:
u = 20 m/s
a = 5 m/s^2
v = 30 m/s
t = ?
Use the first kinematic equation of motion:
v = u + at
t = (v - u)/a = 10/5 = 2 seconds
Answer:x(t)= Acos(wt)
Explanation:
According to Newton's 2nd law,a particle of mass m acted on by a force is given by:Fs=-kx
Where x is displacement from equilibrium
K = spring constant
Therefore X(t) = Acos(2pit/T)
X(t)= Acos(wt)
Answer:
13.6 cm
Explanation:
From Snell's law:
n₁ sin θ₁ = n₂ sin θ₂
In the air, n₁ = 1, and light from the horizon forms a 90° angle with the vertical, so sin θ₁ = sin 90° = 1.
Given n₂ = 4/3:
1 = 4/3 sin θ
sin θ = 3/4
If x is the radius of the circle, then sin θ is:
sin θ = x / √(x² + 12²)
sin θ = x / √(x² + 144)
Substituting:
3/4 = x / √(x² + 144)
9/16 = x² / (x² + 144)
9/16 x² + 81 = x²
81 = 7/16 x²
x ≈ 13.6