A 24.5 kg child sits on a bathroom scale


Kristi Ronning

Please help me with the following 4 questions if you can (I want to double check my answers)......
1. A 24.5 kg child sits on a bathroom scale which is placed on the seat of a swing. What does the scale read when the swing is at rest? The child begins to swing back and forth until she reaches a maximum height of .85 meters (measured vertically) above the low point. What will the scale read as she passes the low point? The swing rope is 3 meters long.
2. A ball of mass .35 kg is swung at the end of a 2.4 m string such that the plane of its path is horizontal and the cirle it moves in has a radius of 1.4 m. Find the tension in the string and the angle which the string makes with the vertical.
3. A ball of mass .45 is attached to a rope and swung in a circle of radius 1.8 m with a centripetal acceleration of 3.1 m/s^2. What is the speed of the ball?
4. A ball of mass .25 kg is attached to a string .75 m long. The ball is swung in a pendulum-type motion such that it has a speed of 6.4 m/s when it reaches the lowest point in its path. What is the corresponding tension in the string?
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Please show us your work, and then we'll show you what's wrong (if anything). Or perhaps you could give us your answers at least and maybe someone nice will check them for you.

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