What is the motional kinetic energy of a 25 kg object moving at a speed of 10 m/s?
1 answer:
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Answer:
Velocity (magnitude) is 98.37 m/s
Explanation:
We use the vertical component of the initial velocity, which is:
Using kinematics expression of vertical velocity (in y direction) for an accelerated motion (constant acceleration, which is gravity):
Now we need to find as a function of
. We use the horizontal velocity, which is always the same as follow:
We know the angle at 3 seconds:
Substitute in
and then solve for
With this expression we go back to the kinematic equation and solve it for initial speed
Answer:
λ = 3 10⁻⁷ m, UV laser
Explanation:
The diffraction phenomenon is described by the expression
a sin θ = m λ
let's use trigonometry
tan θ = y / L
as in this phenomenon the angles are small
tan θ = = sin θ
sin θ = y / L
we substitute
a y / L = m λ
let's apply this equation to the initial data
a 0.04 / L = 1 600 10⁻⁹
a / L = 1.5 10⁻⁵
now they tell us that we change the laser and we have y = 0.04 m for m = 2
a 0.04 / L = 2 λ
a / L = 50 λ
we solve the two expression is
1.5 10⁻⁵ = 50 λ
λ = 1.5 10⁻⁵ / 50
λ = 3 10⁻⁷ m
UV laser