Q. An object weighing 347 N in air is immersed in water after being tied to a string connected to a balance. The scale now reads 316 N. Immersed in oil, the object weighs 328 N. Calculate the density of the object.
Q. When a high-speed passenger train traveling at 169 km/h rounds a bend, the engineer is shocked to see that a locomotive has improperly entered onto the track from a siding and is a distance D = 670 m ahead. The locomotive is moving at 25 km/h. The engineer of the high-speed train immediately applies the brakes.
(a) What must be the magnitude of the resulting constant deceleration if a collision is to be just avoided?
(b) Assume that the engineer is at x = 0 when, at t = 0, he first spots the locomotive. Sketch x(t) curves for the locomotive and high-speed train for the cases in which a collision is just avoided and is not quite avoided. Do this on paper. Your instructor may ask you to turn in this work.