Problem about centroids II

The asking problem: Show that when the distance h is selected to maximize the distance Y from line BB' to the centroid of the shaded area, we also have Y=h. Note: The Y is relating to the centroid Y of the area. The drawing is in word97 format for PC and not for MAC. My problem is I don't know how can I demonstrate this. ...continues

Problems about centroids III

Asking problem: Divide the parabolic spandrel shown into five vertical sections and determinate by approximate means the x coordinate of its centroids; approximate the spandrel by rectangles of the form bdd'b'. Note: The drawing file is in word97 format for PC and not for MAC. My question is how can I determine the area of ...continues

Working with conservation of momentum and collisions.

On a frictionless ice, a block whose mass is A= 6 kg is sliding toward +x with a velocity VA= 8 m/sec, when it collides in a non-elastic collision with a block of mass B= 4 kg moving at an unknown velocity VB. After collision the joined blocks move with momentum P= 84 i + 48 j where i and j are unit vectors. a. Find PB the or ...continues

Block sliding on a sphere

A small block slides from rest from the top of a frictionless sphere of radius R. How far below the top of the sphere does the block lose contact with the sphere? The sphere does not move. Gravity is acting on the block.

True and false question about the relationship between gravitational and kinetic energy.

You drop a ball (initially at rest) from a height of 12 meters above the ground. You can neglect air resistance. Which statements are true about this situation? (Give ALL correct answers) A) The kinetic energy and the gravitational potential energy of the ball are equal when the ball is at a height of 6 meters B) The kine ...continues

True and false questions about the relationship between compression, kinetic energy and potential energy.

A ball of mass m is shot straight up into the air by a spring-loaded launcher. When the spring is compressed by a distance D and then released, the ball has a velocity v out of the launcher and reaches a maximum height H. Ignoring air resistance, which of the following statements is/are true? (Give ALL correct answers) A) If ...continues

True and false questions about the relationships between impulse, momentum, kinetic energy and gravitational potential energy.

Two equal mass balls (one red and the other blue) are dropped from the same height, and rebound off the floor. The red ball rebounds to a higher position than the blue ball. Neglect air resistance. Which of the following statements is/are true about this situation? (Give ALL correct answers) A) During the entire process, m ...continues

Calculating the distance that a box will side with a given mass and coefficients of friction.

A box sits at rest at the top of a frictionless hill, at a height of 40.50 m above the ground. The box slides down the hill, and then continues across rough ground (with coefficient of kinetic friction 0.36) until it stops. What distance will the box slide along the ground before coming to a stop?

Working with spring oscillations and friction.

A block attached to a spring is acted on by a spring with spring constant k and a weak frictional force of constant magnitude f. The block is pulled a distance Xo from the equilibrium and released. It oscillates many times and eventually comes to rest. a) Show that the decrease of amplitude is the same for each cycle of osci ...continues

Calculating velocity in elastic collisions.

A ball of mass m1 = 31.00 grams moving at 15.20 m/s collides head-on with a stationary ball of mass m2 = 116.00 grams. The collision is elastic. What is the velocity of the first ball immediately after the collision?