Dynamic Second Exam

Civil Society in Techno
Key 2nd dynamic
By : Louy Alhami
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If the motor exerts a force F= (600 +2s2) N on the cable. Determine the
speed of the 100-kg crate when it rises to s=15 m. The crate is initially at
rest on the ground.
1. When s=0.6 m, the spring is unstretched and the 10-kg block has a speed
of 5 m/s down the smooth plane. Determine the distance s when the
block stops.
2. The coefficient of kinetic friction between the 20-kg block and the
inclined plane is k=0.2 . If the block is traveling up the inclined plane
with a constant velocity v= 5 m/s, determine the power of force F.
3. The 2-kg pendulum bob is released from rest when it is at A. Determine the
speed of the bob and the tension in the cord when the bob passes through its
lowest position, B.
4. The 2-kg collar is given a downward velocity of 4 m/s when it is at A. If the
spring has an unstretched length of 1 m and a stiffness of k= 30 N/m,
determine the velocity of the collar at s= 1m.
5.
The 37.5 –kg block is released from rest 1.5 m above the plate.
Determine the compression of each spring when the block
momentarily comes to rest after striking the plate. Neglect the
mass of the plate. The springs are initially unstretched.
6. The bucket is hoisted by the rope that warps around a drum wheel. If the angular displacement of the
wheel is  = (0.5 t3+15t) rad, where t is in seconds, determine the velocity and acceleration of the
bucket when t = 3 s.
7. Determine the angular velocity of the spool. The cable warps
around the inner core, and the spool does not slip on the platform
P.
8. If rod AB slides along the horizontal slot with a velocity of 18 m/s,
determine the angular velocity of link BC at the instant shown.
9. At the instant shown, cable AB has a velocity of 3 m/s
and acceleration of 1.5 m/s2, while the gear rack has a
velocity of 1.5 m/s and acceleration of 0.75 m/s2.
Determine the angular acceleration of the gear at this
instant.
10. At the instant  = 45, link DC has an angular velocity of
DC = 4 rad/s and an angular acceleration of DC = 2
rad/s2. Determine the angular velocity and angular
acceleration of rod AB at this instant. The collar at C is
pin connected to DC and slides freely along AB.
11. At the instant shown, car A travels with a speed of 25 m/s, which is
decreasing at a constant rate of 2 m/s2, while car B travels with a
speed of 15 m/s, which is increasing at a constant rate of 2 m/s2.
Determine the velocity and acceleration of car A with respect to
car B.