Classical Mechanics Answers

A rope attached on one end to a vertical wall(forming a 50° angle) helps to support a uniform 800-N beam 7m long the lower end of which is hinged at the same vertical wall (forming a 60° angle) while the other end supports a 1-ton load. Together, the rope, the wall and the beam forms a 50°+60°+70° triangle that points to the right.

Determine tension T in the rope.

A trapezoidal(the left side longer than the right, both sides are parallel) bar 2 m long, horizontally rests balanced(in a state of equilibrium) atop a triangular fulcrum at its center. A box weighing 4 N rests on the left side of the bar, and a crate weighing 6N rests on the right side, both weights are on equal distance from the center.

If the bar weighs 5 N locate its center of gravity.

Let's assume a rigid body of mass "m" has a velocity(ai^+bj^) in two dimensional plane and is now at the position (x1,y1) . It is experiencing a constant force "F" towards the origin(0,0).

What are the conditions for the body to orbit the origin?

6. The average speed of a nitrogen molecule in air is about

6.70 1 102 m/s, and its mass is 4.68 1 10#26 kg. (a) If it

takes 3.00 1 10#13 s for a nitrogen molecule to hit a wall

and rebound with the same speed but moving in the op-

posite direction, what is the average acceleration of the

molecule during this time interval? (b) What average

force does the molecule exert on the wall?

The load was lifted to a height of 1.5 m by a pulley. How far was the free end of the rope pulled to lift that load?

A block of mass m (initially at rest) is dropped from a height h landing onto a spring with spring/force constant k. Determine the maximum distance y that the spring will be compressed?

A ball is thrown at time t = t0 vertically upwards with the speed u. The air resistance can be neglected.  

1. What is the average velocity of the ball, in size and direction, from time t0 until the ball reaches its highest point?
2. What is the mean velocity of the ball, in size and direction, from the time t0 until the ball returns to the height from which it was thrown?

The air in a hot air balloon has been heated to 100 degrees Celsius, and has the same pressure as the air. The balloon is approximately spherical, with a radius of 10 m. How much weight (including the balloon and its basket) can the balloon lift? The answer can be rounded to the nearest ten power.

The rotor of a wind turbine has blades with a length of 40 m. If the wind is 10 m / s, state a roughly estimated power that can be obtained from the wind turbine, by calculating the kinetic energy of the volume of air that passes the rotor every second . The answer can be stated at a ten power when.

a car starts from a standstill and then has a constant acceleration forward by 1 m / s ^ 2.  

1. how big is the car's average speed v from the beginning of the acceleration until it has traveled 200m.  

2. how big is the car's speed v0 when traveling 200m