The earth's gravitational field intensity at its surface is about
(G = 6.7 × 10\(^{-11}\)Nm\(^2\)/kg\(^2\), mass of the earth is 6 × 10\(^{24}\)kg, radius of the earth is 6.4 × 10\(^6\)m, g on the earth = 9.8m/s\(^2\))
The following are parts of the eye
I. Retina
II. Pupil
III. Iris
The correct equivalent in the camera in the same order are
According to kinetic molecular model, in gases
A force of 6N acts horizontally on a stationary mass of 2kg for 4s. The kinetic energy gained by the mass is _________
The momentum of a car moving at a constant speed in a circular track
