Mechanics | Relativity Answers

A 3-kg object moving to the right on a frictionless, horizontal surface with a speed of 2 m/s collides head on and sticks to a 2-kg object that is initially moving to the left with a speed of 4 m/s. After the collision, which statenoent is true?
(a) The kinetic energy of the system is 20 J. (b) The momentum of the system is 14 kgm/s. (c)
The kinetic energy of the system is greater than 5 J but less than 20 J. (d) The momentum of the system is 22?

A particle of mass m moves with momentum of magnitude p. (a) Show that the kinetic energy of the particle is K = p^2 / 2m. (b) An object has a kinetic energy of 275 J and a momentum of magnitude 25.0 kgm/s. Find the speed and mass of the object.

In a nuclear collision, a proton A is incident on a stationary
neighboring proton B with a velocity of 3.00 x 10 ms- .
After impact A moves in the direction BC
with a velocity of 1.50 x 10 m/s. B then moves in the direction
BD. If BC makes an angle of 60degrees with the initial direction (AB)
of A and BD makes an angle G with it ;
(i) Calculate the speed of B along BD and the angle teta
verify whether or not the collision is elastic.

wo people are pulling a table (of mass 3 kg) on a hard surface. One person is pulling with
horizontal force of 10 N to the left, the other with a horizontal force of 20 N at -30 ° to the
horizontal. What is the net force on the table?

A non-uniform plank AB of mass 20 kg and length 2 m is pivoted at its midpoint. The plank is in equilibrium in a horizontal position when a particle of mass 5 kg is placed 40 cm from A and another particle of mass 8 kg is placed 30 cm from B. Find the distance of the centre of mass of the plank from A.

A Ferris wheel with a radius of 8.0 m makes 1 revolution in 10 s. When a passenger is at the top, he releases a ball. How far from the point on the ground directly under the release point does the ball land?

A flywheel, together with its shaft , has a total mass of 300kg, and its radius of gyration is 900mm. If the effect of bearing friction is equivalent to a couple of 70Nm, calculate the breaking torque required to bring the flywheel to rest from a speed of 12rev/s in 8s.

A steel cylinder of 500mm outside diameter and 200mm inside diameter is set in rotation about its axis. If the cylinder is 900mm long, of density 7800kg/m^3, calculate the torque required to give an angular acceleration of 0.5rad/s^2.

You throw a ball with a speed of 25m/s at an angle of 40degrees above horizontal directly toward a wall. The wall is 22m from the release point of the ball. (a) How long does the ball take to reach the wall? (b) How far above the release point does the ball hit the wall? (c) What are the vertical and horizontal components of its velocity as it hits the wall? (d) When it hits, has it passed the highest point on its trajectory?

A 72N force accelerates an object with mass (m1) by 5.0 m/s2. The same force acts on another object with mass (m2) and accelerates (m2) by 20.0 m/s2. What acceleration will the same force impart to the two objects when they are joined together?