Answer:
ΔK = -6 10⁴ J
Explanation:
This is a crash problem, let's start by defining a system formed by the two trucks, so that the forces during the crash have been internal and the moment is preserved
initial instant. Before the crash
p₀ = m v₁ + M 0
final instant. Right after the crash
p_f = (m + M) v
p₀ = p_f
mv₁ = (m + M) v
v =
we substitute
v =
3
v = 1.0 m / s
having the initial and final velocities, let's find the kinetic energy
K₀ = ½ m v₁² + 0
K₀ = ½ 20 10³ 3²
K₀ = 9 10⁴ J
K_f = ½ (m + M) v²
K_f = ½ (20 +40) 10³ 1²
K_f = 3 10⁴ J
the change in energy is
ΔK = K_f - K₀
ΔK = (3 - 9) 10⁴
ΔK = -6 10⁴ J
The negative sign indicates that the energy is ranked in another type of energy
From among the choices provided, the better choice is the upper-case letter '<em>T </em>'. That symbol can conveniently be used to represent the words "true" or "truth", which is exactly the reason that it is the better choice for a response, since the complicated statement at the beginning of the question is completely true in its every detail, nuance, jot and tittle.
Hi there!

To calculate the tension, we must calculate the acceleration of the system.
Begin with a summation of forces:
∑F = -M₁gsinФ + T - T + M₂g
Simplify and solve for acceleration: (Tensions cancel out)

Plug in values. Let g = 10 m/s²

Now, to find tension, let's sum up the forces acting on ONE block. For simplicity, we can look at the hanging block:
∑F = -T + W
ma = -T + W
Rearrange to solve for T:
T = W - ma
We know the acceleration, so plug in the values:
T = (8)(10) - (8)(5.91) = 32.73 N