A crate of mass 25 kg rests on a smooth horizontal floor. A rope exerts the force (72i+34j)(72\mathbf{i}+34\mathbf{j})(72i+34j) N on the crate, where i\mathbf{i}i is horizontal in the direction of motion and j\mathbf{j}j is vertically upwards. Use g=9.8 m s−2g=9.8\text{ m s}^{-2}g=9.8 m s−2.
Find the acceleration of the crate.
Find the normal contact force exerted by the floor on the crate.
49 exam-style questions on OCR (MEI) A Level Maths 3.5 Newton's Laws of Motion, covering 3.5.1 Meaning of Newton's three laws, 3.5.2 Equation of motion, 3.5.3 Equation of motion for a particle in a straight line, 3.5.4 Model a system of connected particles, 3.5.5 Equations of motion for individual particles, 3.5.6 System with no relative motion as a single particle, and 3.5.7 Equation of motion in a straight line or plane (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.