Duration: 45 min
SI Session 1
SI Leader: Mkhululi Gumede
Date: 09 Aug 2024
Question 1
Determine the magnitude and direction of the friction force acting on the 100 kg
block if P = 130 N. The coefficient of static friction is 0.2 and the coefficient of
kinetic friction is 0.17. (6 marks)
Question 2
Two identical blocks (mass m) are connected by an ideal string. The coefficient of
static friction between all contacting surfaces is 0.3. Determine the angle θ at which
the blocks begin to slide. (5 marks)
Question 3
The uniform rod has a mass of 10-kg and rests on the inside of the smooth ring at B
and on the ground at A. If the rod is on the verge of slipping and the coefficient of
static friction between the ladder and the floor is µ = 0.4, determine the magnitude
of the force at B and the normal force at A. (3 marks)
Duration: 45 min
SI Session 2
SI Leader: Mkhululi Gumede
Question 4
The acceleration of a particle moving along a straight line is a = -cv3, where c is a
constant.
a) If the speed of the particle is v0, what distance does the particle travel before
its speed decreases to v0/2? (3 marks)
b) How long does it take for the speed of the particle to reduce from v0 to v0/2? (3
marks)
Question 5
The rocket sled is travelling at 240 m/s when it hits a water break. The subsequent
acceleration due to water resistance is a = −0.003v2 m/s2, where is the speed in m/s.
Determine the distance covered by the rocket sled as its speed decreases from 240
m/s to 40 m/s. (3 marks)
Question 6
Engineers analysing the motion of a linkage determine that the velocity of an
attachment point is given by v = A + 4s2 m/s, where A is a constant. When s = 2 m, its
acceleration is measured and determined to be a = 320 m/s2. What is its velocity of
the point when s = 2 m? (3 marks)
Question 7
A steel ball is released from rest in a container of oil. Its downward acceleration is
a = 2.4 − 0.6v cm/s2, where v is the ball’s velocity in cm/s. What is the ball’s
downward velocity 3s after it is released? (4 marks)