Answer:
Produces heat in various parts of machines.
Due to friction we have to exert more power in machines.
It opposes the motion.
Due to friction, noise is also produced in machines.
Due to friction, engines of automobiles consume more fuel which is a money loss.
Explanation:
Source: https://www.quora.com/What-are-the-disadvantages-of-friction
Kinetic energy is the answer to your question.
Momentum is a product of mass and the velocity of a body. The initial momentum is always equal to the final momentum during collisions between two bodies.
Therefore; M1U1 +M2U2 = M1V1+ M2V2, where m1 is the mass of tracey and m2 is the mass of jonas, while u is the initial velocity and v is the final velocity.
(32 ×0)+ (45×0) = (32 × v1) + (45 × 0.50)
0 = 32V1 + 22.5
32 V1 = -22.5
V1 = - 0.703 ( negative indicates difference in direction)
There, Tracey's speed will be 0.703 m/s