Q.2.11. Vectors A ,B and C are 4 units north, 3 units west and 8 units east , respectively. Describe carefully (a)AxB (b)AxC (c)BxC
Q.2.12. The torque or turning effect of force about a given point is given by rxF where r is the vector from the given point to the point of application of F. Consider a force F =-3 î + ĵ +5 ḵ (newton) acting on the point 7 î + 3 ĵ +ḵ (m). What …
Q.2.13. The line of action of force, F= î -2 ĵ , passes through a point whose position vector is (-ĵ + ḵ). Find (a) the moment of F about the origin, (b) the moment of F about the point of which the position vector is î + ḵ.
Q.2.14. The magnitude of dot and cross products of two vectors are 6√3 and 6 respectively. Find the angle between the vectors.
Q.2.15. A load of 10.0N is suspended from a clothes line. This distorts the line so that it makes an angle of 15° with the horizontal at each end. Find the tension in the clothes line.
Q.2.16. A tractor of weight 15,000N crosses a single span bridge of weight 8000N and of length 21.0m. The bridge span is supported half a meter from either end. The tractor’s front wheels take 1/3 of the total weight of the tractor, and the rear wheels are 3m behind the front wheels. Calculate the force …
Q.2.17. A spherical ball of weight 50N is to be lifted over the step as shown in the fig. 2.23.Calculate the minimum force needed just to lift it above the floor.