An object weighing 345 N in air is immersed in water after being tied to a string connected to a balance. The scale now reads 250 N. Immersed in oil, the object appears to weigh 295 N.
Well, well, well, it seems like our object is quite the prankster! It's playing hide-and-seek with its real weight. In air, it weighs 345 N, but in water, it decides to go on a diet and scales down to 250 N. Talk about making a splash!
But wait, there's more! When this mischievous object is submerged in oil, it decides to gain a little weight back, just to confuse us. It tips the scales at 295 N. Oh, you tricky little thing!
I'm not sure what this object's end goal is, maybe it's auditioning for a magic show. But hey, it's a good thing we have a balance to keep tabs on its weight antics. Keep an eye on this one, though. Who knows what kind of pranks it'll pull next!
To explain why the object weighs different amounts in air, water, and oil, we need to understand the concept of buoyancy. When an object is submerged in a fluid, it experiences an upward force called buoyant force. This force is exerted by the fluid and is equal to the weight of the fluid displaced by the object.
In air, the object has a weight of 345 N as measured by the scale. This is equal to the force of gravity acting on the object. The buoyant force in air is negligible because the density of air is much lower than the density of the object. Therefore, the scale reads the actual weight of the object.
When the object is immersed in water, it appears to weigh 250 N on the scale. The decrease in weight is due to the buoyant force exerted by water. The object displaces an amount of water with a weight equal to 345 N - 250 N = 95 N. So, the buoyant force in water is 95 N, which reduces the apparent weight of the object on the scale.
Similarly, when the object is immersed in oil, it appears to weigh 295 N on the scale. Again, the decrease in weight is due to the buoyant force exerted by oil. The object displaces an amount of oil with a weight equal to 345 N - 295 N = 50 N. So, the buoyant force in oil is 50 N, which reduces the apparent weight of the object on the scale.
In summary, the apparent weight of the object on the scale decreases when it is immersed in a fluid due to the buoyant force exerted by that fluid.