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1.A freight train has a mass of 1.3 ? 10 7 kg. If the locomotive can exert a con

ID: 1278856 • Letter: 1

Question

1.A freight train has a mass of 1.3 ? 107 kg. If the locomotive can exert a constant pull of 6.5 ? 105 N, how long does it take to increase the speed of the train from rest to 62 km/h?

2.A 907-kg car starts from rest on a horizontal roadway and accelerates eastward for 5.00 s when it reaches a speed of 20.0 m/s. What is the average force exerted on the car during this time?

a.) Find the acceleration of the 2 objects and the tension in the string.

a=__________m/s2   T= ____________N

b.) Use the value from the part A to help you work this exercise. What if an additional mass is attached to the ball? How large must this mass be to increase the downward acceleration by 30%?

Consider the figure below. Find the tension in each cable supporting the 572-N cat burglar. (Assume the angle 6 of the inclined cable is 32.0 degree ) inclined cable Suppose the horizontal cable were reattached higher up on the wall. Would the tension in the inclined cable increase, decrease, or stay the same?

Explanation / Answer

1.

apply F = ma

so accleration a = 8,3e5/1.7e7

a = 0.0488 m/s^2

use V = u +at

use 1kmph = 5/18 m/s

t = (64*5/18)-0/0.0488

t = 364.298 secs

t = 6.07 mins

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2.

2. accleration a = V/t = 20/5 = 4 m/s^2

so force F = ma = 907 * 4 = 3628 N

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