3. 500ml of 60oC water at is added to a beaker. Water’s specific heat is 4.186 J/g °C. You have 40ml of and unknown substance that you add to the same beaker. The unknown substance’s specific heat is 14.3/goC The final temperature of the beaker is 45oC. What was the initial temperature of the unknown substance?

Ahorizontal wire is tied to supports at each end and vibrates in its second-overtone standing wave. the tension in the wire is 5.00 n, and the node-to-node distance in the standing wave is 6.28 cm. (a) what is the length of the wire? (b) a point at an anti- node of the standing wave on the wire travels from its maximum upward displacement to its maximum downward displacement in 8.40 ms. what is the wire's mass?

An object weigh 40n in air ,weigh 20n when submerged in water, and 30n when submerged in a liquid of unknown liquid density. what is the density of unknown of liquid?

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. which statement is true? 1-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of higher voltages. 2-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of lower voltages. 3-at any point, the electric field is parallel to the equipotential line at that point.