A bicycle with 0.80 m diameter tires is coasting on a level road at 5.6 m/s. A small blue dot had been painted on the tread of the rear tire. What is the speed of the blue dot when it is 0.4m above the road.

the speed of the blue dot when it is 0.4m above the road is 7.92 m/s

Explanation:

If the blue dot is 0.4m above the road, then it is at exactly half of the tire diameter. Thus, the vertical component on the velocity (Vj) = 5.6 m/s and the horizontal component of the velocity(Vi) is 5.6 m/s.

V = (5.6i + 5.6j)

From vector laws, the magnitude of the vector becomes;

Therefore, the speed of the blue dot when it is 0.4m above the road is 7.92 m/s

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.