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
1212.54 is what 550 kgs is equal to the weight of the car
A. Upstream refers to the motion of the swimmer where he is against the current. The resultant speed of the swimmer is equal to the difference of the velocity or speed in still water and that of the river. The time it requires to cover the distance is calculated through the equation,
t = d / s
where t is time, d is distance, and s is speed. Substituting the known values,
t = 1000 m / (1.2 m/s - 0.5 m/s) = 1,428.57 seconds
(b) The time it requires for the swimmer to swim in still water,
t = 1000 m / (1.2 m/s) = 833.33 seconds
(c) Intuitively, it takes longer to cover the distance when there is current because the current will serve as resistance to the motion of the swimmer, partially moving it backwards instead of forward.
Answer:
charge = electrons + protons
=92+92
=184
If it is GAINING mass, the kinetic energy increases because it's still moving. If it stopped, it would then become potential energy.
yw XD
(just answered the same question just different user)
