A man of mass 80 kg is standing stationary in the middle of a train carriage. The train is moving horizontally (towards the right) with a constant speed of 20 m/s, and the carriage is L = 20 m long. Suddenly, the train starts to accelerate uniformly with a = 2 m/s2 horizontally
a) Is the reference frame of the train now an inertial frame? Design an experiment that allows you to find out.
b) Draw a free-body diagram of the man. Label the forces appropriately and explain their physical origin (one line each will suffice).
c) If the coefficient of friction between the man’s shoes and the ‘floor’ of the train is μ = 0.1, what is the maximum time that the man takes to hit the back of the train carriage? For simplicity, you can assume that the coefficient of static friction is the same as the coefficient of kinetic friction. Assume that there are no obstacles between the man and the back of the train.
d) How does your answer change if the coefficient of friction is 0.3 instead? Ex- plain.
A man of mass 80 kg is standing stationary in the middle of a train carriage....
16 As shown in Figure (5), block A, with a mass of 10 kg, slides down the slope from stationary to hit block B, with a mass of 5 kg. Block A travels 5 m immediately before hitting block B. The sliding friction coefficient between the blocks and the slope is = 0.3. O-x-y is a sta- tionary inertial reference frame. The slope angle, 0-45°. What is the speed of block A immediately before hitting block B with respect to...
In a study of the
biomechanics of the tug-of-war, a 2.0-m-tall, 80.0-kg competitor in
the middle of the line is considered to be a rigid body leaning
back at an angle of 30.0?
to the vertical. The competitor is pulling on a
rope that is held horizontal a distance of 1.5m from his feet (as
measured along the line of the body). At the moment shown in the
(Figure 1) , the man is stationary and the tension in the...
Name 37) You have been hired as an expert witness in a crash investigation. Car A of mass 1900 kg crashed into stationary car B of mass 1000 kg. You measure the coefficient of kinetic friction between the locked tires a was in park so the tires did not turn). Car A hits car B, locking bumpers so that they s bef nd the road to be 0.6 (car B kid off together. They skid 20 m ore coming to...