Suppose you are standing on a bathroom scale next to a sink. How does the reading on the scale change if you push down on the sink?
Thank you for using the Jiskha Homework Help Forum again. If you push down on the sink you are releiving some of the weight on the scale. How much depends upon the force with which you are pushing down on the sink. Try it!
When you push down on the sink while standing on a bathroom scale, the reading on the scale will increase. Here are the step-by-step details:
1. Step on the bathroom scale: Before you push down on the sink, step on the bathroom scale in a normal position without applying any external force.
2. Initial reading: Take note of the initial reading displayed on the scale. This reading represents your weight or the force exerted by your body on the scale due to gravity.
3. Pushing down on the sink: Place your hands on the sink and push down. By exerting a force on the sink, you create an upward reaction force on your body through Newton's third law of motion.
4. Transfer of forces: The reaction force from pushing down on the sink is transferred to the floor. The floor then exerts an equal and opposite force upward to support your body, counteracting the force exerted on the sink.
5. Increased reading on the scale: Since the floor exerts an upward force on your body, the normal force acting on your body increases. The normal force is the force exerted by a surface to support an object resting on it. This increased normal force is displayed as an increased reading on the bathroom scale.
In summary, when you push down on the sink, the reaction force causes an increase in the normal force acting on your body, leading to an increased reading on the bathroom scale.
The reading on the bathroom scale will not change if you push down on the sink. This is because the scale measures the force exerted on it by an object, in this case, your weight. When you push down on the sink, you are exerting a force on it, but this force does not directly affect the scale.
To understand why, let's break it down step by step:
1. When you stand on the scale, its internal mechanisms measure the force exerted on it due to your weight. This force is transferred through your body and onto the scale, which then displays the corresponding reading.
2. When you push down on the sink, that force is transmitted through the sink into the floor or the supporting structure of the bathroom. It does not pass directly onto the scale.
In other words, the scale only measures the force exerted on its surface and cannot directly sense or account for forces acting on objects next to it, like the sink. Therefore, the reading on the scale remains unchanged when you push down on the sink.
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