Answer:
I think u are traeling at speed of light and not ur friend
Explanation:
Answer:
v = 9.04 m / s
Explanation:
For this exercise we can use the relation that the work of the non-conservative force (friction) is equal to the variation of the mechanical energy of the system.
W = Em_f - Em₀ (1)
Starting point. Lower slope
Em₀ = K = ½ m v²
highest point. Where is the skier at a height h
Em_f = U = m g h
The work of rubbing
W = -fr x
the negative sign is because the friction force opposes the movement.
Let's set a reference system where the x axis is parallel to the slope and the y axis is perpendicular
let's use trigonometry to break down the weight
cos θ = W_y / W
sin θ = Wₓ / W
W_y = W cos θ
Wₓ = W sin θ
Y axis
N - Wₓ = 0
N = mg sin θ
X axis
fr = m a
the friction force has the expression
fr = μ N
fr = μ mg sin θ
we look for the job
W = - μ mg sin θ x
where x is the distance along the slope
we substitute in 1
-μ mg sin θ x = mg h - ½ m v²
let's use trigonometry to find the distance x
tan 30 = h / x
x = h / tan 30
we substitute
- = m gh - ½ m v²
we use
tan 30 = sin30 / cos30
v² = 2g h + 2 μ g h cos 30
v =
let's calculate
v =
v = 9.04 m / s
Answer:
D
Explanation:
im not sure just sounds right
Answer:
63.8 V
Explanation:
We are given that
Potential difference,V=140 V
We know that
According to question
In series
Potential across 1.2 square cm=
Hence, the voltage across the 1.2 square cm wire=63.8 V
Answer:
<em>The kinetic energy is 600 J</em>
Explanation:
<u>Mechanical Energy</u>
The principle of the conservation of mechanical energy states that the total mechanical energy in a system remains constant as long as the only forces acting are conservative forces.
The mechanical energy is defined as the sum of the potential plus kinetic energies:
E = U + K
Where E is the total mechanical energy, U is the gravitational potential energy and K is the kinetic energy.
Solving for K:
K = E - U
The system described has a total mechanical energy of E=950 J and gravitational potential energy of U=350 J, thus:
K = 950 J - 350 J
K = 600 J
The kinetic energy is 600 J