Fig 1.2 shows a force of 6.0N acting at 30o to the horizontal.
Calculate the component if the force that acts
(i) horizontally
horizontal component …………………… N
(ii) vertically
vertical component ……………………..N
(2)
Fig 1.3 shows two strings supporting an object of weight 12N. The tension in one of the strings is 6.0N. The tension in the other string is T.
(i) Calculate the magnitude of the vertical component T in order for the object to be in equilibrium.
Vertical component ……………………………….(N)
(2)
(ii) Hence calculate the magnitude of T
Magnitude of T ………………………………………N
(2)
A child sits on a swing and is pulled by a horizontal force P so that the chains make an angle with the vertical of 35o. Fig 1.3 shows the forces acting in this position.
The combined mass of the child and swing seat is 28kg.
(a) Calculate the combined weight of the child and the swing seat
Weight ……………………N
(2)
(b) Use a labeled vector triangle to determine the force P required to hold the swing stationary in the position shown in Fig 1.3
Force ……………………..N
(4)
(c) State and explain what happens to the tension in the chains if the swing is pulled so that the chains make a larger angle with the vertical. A numerical answer is not required.
(2)
In a down hill ski race the total vertical drop is 556m down a slope that makes an angle of 20.5o with the horizontal. The weight of a skier (including his equipment) is 900.7N.
a) Calculate the loss of gravitational potential; energy of the skier.
(3)
b) The total distance travelled by the skier (assume that the slope is perfectly smooth and uniform.
(2)
c) The average resistive force acting against the skier is 250.4N.
(i)Calculate the work done against this resistive force.
(3)
(ii) If the skier does no work, calculate
1) His kinetic energy as he passes the finish.
(2)
2) His speed as he passes the finish.
(2)
A pendulum consisting of a bob of mass 7kg hanging on a long string is pulled to the side so that it is 0.2m from its position of rest. The bob is then released. What will be its velocity when it passes through the lowest point along its path?
Velocity ………………………
(2)