Gavin doesn't like stepping on the cold stone floor of his room on winter mornings. He is usually careful to walk on the rugs laid over parts of the floor. One day, he wonders why the rugs feel warmer than the stone floor. Since the rugs sit on the bare floor all the time, he thinks they should be at about the same temperature. Which of the following is a good hypothesis Gavin can use to help satisfy his curiosity?

Each student aligns the edge of the object with the left edge of the ruler as shown above. all four students read the ruler with a measurement of 4.6 cm. which statement describes the data they collect? i believe the answer is: the data have poor precision and poor accuracy because of a systematic error.

The figure is missing but we can answer anyway.the correct answer is "releasing the string". in fact, when the person is holding the bow and the arrow, the kinetic energy of the arrow is still zero (because the arrow is not moving). the moment the arrow is released, it acquires a velocity v, so its kinetic energy will become different from zero: where m is the mass of the arrow and v its velocity.  all the other options, instead, do not increase the kinetic energy of the system: -  pulling farther back on the string : this will just increase the elastic potential energy of the system-  holding the arrow higher: this will increase the gravitational potential energy of the system (which is given by u=mgh, where h is the height above the ground)-  decreasing the mass of the arrow: this will decrease the gravitational potential energy of the system (which is given by u=mgh, where m is the mass)