Located on level land, the flat-roofed schoolhouse is 12 meters wide by 7 meters high. Where should he stand so that the ball may clear the wall without a lot of effort, or as it is more often called, with a low initial velocity? '1

Given: The ball strikes the smooth wall with a velocity (v b) 1 = 20 m/ s. The coefficient of restitution between the ball and the wall is e = 0.75. Find height max and distance after impact. (Vb)2 0 30° (Vb)₁ = 20 m/s Ay X

A small boat coasts at constant speed under a bridge.A heavy sack of sand is dropped from the bridge onto theboat. The speed of the boat(a) increases.(b) decreases.(c) does not change.(d) Without knowing the mass of the boat and the sand,we can’t tell.

4. For an object in free fall near the surface of the earth or another planet, how is momentum conserved? (Hint: Momentum is conserved throughout the falling process, not just before the drop and after it lands.)

b) A vertical pile of mass 150 kg is driven 120 mm into the ground by the blow of a 1100 kg hammer, which falls through 800 mm. assuming the hammer and pile remain in contact, determine the following: i) The velocity of the hammer just before impact ii) The velocity immediately after impact iii) The resistive force of the ground, assuming it to be uniform

A person of mass M having a good traction with the surface of support can provide a rock of mass m = 0.02 M with horizontal velocity of 5.00 m/s . If the same effort is generated while standing on a very slippery surface, define velocity of the same rock relatively to the person.

(1) A car with mass 996 kg moving at 28 m/s hits a giant bag of marshmallows.  The bag slows the car down, but it is unable to completely stop it because it ruptures at Dt = 1.8 s after the car hits, scattering marshmallows all over the countryside.  Suppose the bag exerts a force on the car that depends on time (t) given by F = -At2; A = 7.2 x 103 N/s2 when t is in seconds   (2) Two objects, moving towards each other with speed v, collide head on, stick together, and then move on with speed v/4 after the collision. (a) What is the ratio of the kinetic energy after the collision to the kinetic energy before the collision? (answer: 1/16) (b) What is the ratio of the mass of the more massive object to the mass of the less massive object? (answer: 5/3)

5) The center of mass of a two-particle system is at the origin. One particle is located at (3.0 m, 0) and has a mass of 2.0 kg. What is the location of the second mass of 3.0 kg?

If you drop a sheet of paper and a book side by side, the book falls faster than the paper. Why?

In an elastic collision in which there are no external forces, which of the following is true?         Only the total momentum is conserved.       Only the kinetic energy is conserved       Both the total momentum and kinetic energy are conserved.       Both the total momentum and kinetic energy are not conserved.