Engineering Mechanics
Assignment – 6
Module - 6 Kinetics of Particle
1. A spring is used to stop 100 kg package which is moving down a 30o incline. The spring has constant
k=30 kN/m is held by cables so that it is initially compressed by 90mm, If the velocities of package is
5m/s, When it is 9m from spring. Determine the maximum additional deformation of spring in
bringing the package to rest. Assume coefficient of friction between
block and incline as 0.2.
Ans: x =0.452 m
2.
A spring of stiffness k is placed horizontally and a ball of mass m
strikes the spring with a velocity v. Find the maximum compression
of the spring. (Take m=5kg, k=500N/m, v=3m/s).
Ans: δ =0.3 m
3. Explain work energy principle.
4. Explain what is coefficient of restitution. A tennis ball of 75gm
mass falls on ground through a height of 3 m. How many times it
will bounce before it comes to rest? Take e=0.7
Ans:
5. Two smooth spheres A and B having a mass of 2 kg and 4 kg respectively collide with initial velocities
as shown in Fig. If the coefficient of restitution for the spheres is e=0.8, determine the velocities of
each sphere after collision.
Ans: VAX =-2.75 m/sec
6. A ball drops from the ceiling of a room. After rebounding twice from the floor it reaches a height
equal to half that of ceiling find the coefficient of restitution.
Ans: e = 0.841