2. A boy on a 2kg skateboard initially at rest tosses an 8kg jug of water in the forward direction. If the jug has a speed of 3.0m/s relative to the ground and the boy and skateboard move in
opposite direction at 0.60m/s, find the boy's mass.

If the radius of curvature of the cornea is 0.75 cm when the eye is focusing on an object 36.0 cm from the cornea vertex and the indexes of refraction are as described before, what is the distance from the cornea vertex to the retina? express your answer to two significant

Give one example to show that when substances are mixed, it may result in a chemical or a physical change depending on the conditions.

Smallest intensity of a stimulus that you can detect 50 percent of the time is