A62.4 g mass is attached to a horizontal spring with a spring constant of 17.3 n/m and released from rest with an amplitude of 23.7 cm. what is the speed of the mass when it is halfway to the equilibrium position if the surface is frictionless? answer in units of m/s.

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

By what factor does the drag force on a car increase as it goes from 65 to 110 km/h?

Asailboat is traveling to the right when a gust of wind causes the boat to accelerate leftward at 2.5m/s2 for 4s. after the wind stops, the sailboat is traveling to the left with a velocity of 3.0m/s.assuming the acceleration from the wind is constant, what was the initial velocity of the sailboat before the gust of wind? answer using a coordinate system where rightward is positive.