Question

Two carts are involved in an inelastic collision. Cart A with mass 0.900 kg hits cart B with mass 0.550 kg (initially at rest). The two carts stick together after the collision and continue to move along together. Cart A has an initial velocity of 0.29 m/s.
a. What is the final velocity of the two-cart system?
b. What is the initial kinetic energy of cart A?
c. What is the initial kinetic energy of cart B?
d. What is the final kinetic energy of the system?
e. Is kinetic energy conserved for inelastic collisions?
f. Is momentum conserved for inelastic collisions?

Answer 1

Answer:

a)  v = 0.18 m / s, b)  K₀ₐ = 0.0378 J, c) K_{ob}= 0, d)  K = 0.02349 J,

Explanation:

a) For this exercise we must define a system formed by the two cars, so that the forces during the collision are internal and the moment is conserved

initial instant. Before the hole

         p₀ = ma v₀ₐ

final intnate. After the crash

         p_f = (mₐ + m_b) v

the moment is preserved

         p₀ = p_f

         mₐ v₀ₐ = (mₐ + m_b) v

         v = $\frac{m_a}{m_a+m_b} \ v_{oa}$

       

let's calculate

         v = $\frac{0.900}{0.900+0.550} \ 0.29$

         v = 0.18 m / s

in the same direction of the movement of carriage A

b) the initial kinetic energy car A

         K₀ₐ = ½ m  v₀ₐ²

         K₀ₐ = ½ 0.900 0.29²

         K₀ₐ = 0.0378 J

c) kinetic energy of carriage B

          k_{ob} = 0

because the car is stopped

d) the kinetic energy of the system

          K = ½ (mₐ + m_b) v²

           K = ½ (0.900 + 0.550) 0.18²

           K = 0.02349 J

E) we see that part of the kinetic energy is lost, therefore the scientific reeling is not conserved in inelastic collisions

F) and momentum is conserved since it is equal to the variation of the moment and this is conserved in all collisions