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First, we will get the resultant force: The direction of the force due to the person's weight is vertically down. weight of person = 700 newton
Assume that the force exerted by the arms has a vertically upwards direction. Force exerted by arms = 2*355 = 710 newtons
Therefore, the resultant force = 710 - 700 = 10 newtons (in the vertically upwards direction)
Now, we will get the mass of the person. weight = 700 newtons weight = mass * acceleration due to gravity 700 = 9.8*mass mass = 71.428 kg
Then we will calculate the acceleration of the resultant force: Force = mass*acceleration 10 = 71.428*acceleration acceleration = 0.14 m/sec^2
Finally, we will use the equation of motion to get the final speed of the person. V^2 = U^2 + 2aS where: V is the final velocity that we need to calculate U is the initial velocity = 0 m/sec (person starts at rest) a is the person's acceleration = 0.14 m/sec^2 S is the distance covered = 25 cm = 0.25 meters
Substitute with the givens in the above equation to get the final speed as follows: V^2 = U^2 + 2aS V^2 = (0)^2 + 2(0.14)(0.25) V^2 = 0.07 V = 0.2645 m/sec
Based on the above calculations: The person's speed at the given point is 0.2645 m/sec
Therefore, the minimum distance L you can place a screen from the double slit that will give you an interference pattern on the screen that you can accurately measure using an ordinary 30 cm (12 in) ruler. = 3.6 m
