Alex drops a soccer ball and a table tennis ball from the top of a ladder. He wants to compare the velocities of the balls just before they hit the ground.
Which formula should Alex use to calculate the velocity of each ball,
assuming they are in free fall?

Which two objects have the greatest gravitational force acting between them

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

Ababy stroller is a rest on top of a hill which is 10 m high. the stroller and baby have a mass of 20 kg. what is the potential energy of the baby and stroller?