a) The component of the acceleration due to gravity down an inclined plane is 3.8 m s?2. Determine the angle the plane makes with the horizontal.Calculate how much work is done when a 7.5 kg object is accelerated from rest to a velocity of 12 m s?1.h) Determine the power required to lift a 5.0 kg object through a height of 80 m in a time of 3.5 s.i) The velocity of a 57 gram tennis ball changes from 11 m s?1 to ?15 m s?1 when it is hit by a racquet. Calculate the impulse.j) A copper bar of length 1.5 m has a cross-sectional area of 4.0x10?4 m2. If there is a constant temperature difference of 50 K between the ends of the bar, determine the heat energy which flows along the bar in 2.5 minutes.
Q1a: agSinΘ rearranged gives Θ Sin^-1 a/g Sin^-1 3.8/9.8 23 deg (g) use formula for KE because work One joule of work is done when a force of one Newton moves through a distance of one metre in the direction of the force. and energy is the capacity to do work, so KE1/2 mv^2 1/2 (7.5) (12)^2 540J 5.4x10^2 J
