In a video game, a ball moving at 0.6 meter/second collides with a wall. After the collision, the velocity of the ball changed to -0.4 meter/second. The collision takes 0.2 seconds to occur. What’s the acceleration of the ball during the collision? Use a=v-u/t

What is the earliest point in the universe that we can observe? why can’t we see back further than this?

James is trying to prove newton's 2nd law of motion. he tries to move four different objects with different masses, shapes, and sizes from point a to point b. the objects are a toy car, a car, a refrigerator, and a kitchen table. after some experimentation, he finds that force is dependent on the mass of the object, rather than it's size or shape. the object that takes the most force to move is the

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.