A stone of mass 20g is released from a catapult whose rubber has been stretched through 4cm If the force constant of the rubber is 200Nm calculate the velocity with which the stone leaves the catapult

Anybody wanna ? (picture included? )

Awave has a wavelength of 7 mm and a frequency of 19 hertz. what is its speed?

On a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 3.00 m/s.(a) what are the magnitude and direction of the velocity of the red glider after the collision? (b) is this collision elastic?