00 A particle of mass 0.34 kg moving on a frictionless horizontal air track
at 1.2 m/s, collides elastically with a second particle lying at rest. After
the collision, the first particle continues in its original direction at 0.66
m/s. What is the mass of the second particle?

Which type of microscope would allow the viewer to see ribosomes inside a cell?

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 710 n/m. it is initially at rest on an inclined plane that is at an angle of θ = 23° with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is μk = 0.19. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. a) what is the block's initial mechanical energy? b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Idon’t quite understand this problem