Question

directions: answer the following questions below. take your time and good luck! 1. the bobsled is an event in the winter olympics. in this event, each sled and its riders speed down an icy track. which factor(s) affect how much kinetic energy the sled and its team have when the sled crosses the finish line? a. mass only b. speed and time c. speed and mass d. speed, mass, and time 2. lance is a 60 - kg runner who, on a good day, runs at a speed of 5 m/s. what is his kinetic energy when he runs at this speed? a. 150 j b. 300 j c. 750 j d. 1500 j 3. bonito has potential energy while he is in the starting blocks, getting ready to run his 5 - kilometer race. which of the following statements are true about his potential energy? choose the three statements that apply. a. it can do work. b. it is stored energy. c. it might be used later. d. it can be changed into kinetic energy. 4. george rolled four different types of paper into four different cylinders. identical 10 - cm rubber bands were placed around the cylinders to hold the paper in place. each number in the answer choices is the diameter of one of the cylinders. which cylinder has the rubber band with the greatest elastic potential energy? a. 05 cm b. 10 cm c. 20 cm d. 25 cm

Explanation:

Step1: Recall kinetic - energy formula

The formula for kinetic energy is $K = \frac{1}{2}mv^{2}$, where $m$ is mass and $v$ is speed. So kinetic energy depends on mass and speed.

Step2: Answer question 1

Based on the kinetic - energy formula, the factors that affect the kinetic energy of the sled and its team when crossing the finish line are speed and mass. So the answer to question 1 is C.

Step3: Calculate kinetic energy for question 2

Given $m = 60\ kg$ and $v = 5\ m/s$, use the formula $K=\frac{1}{2}mv^{2}$. Substitute the values: $K=\frac{1}{2}\times60\times5^{2}=\frac{1}{2}\times60\times25 = 750\ J$. So the answer to question 2 is C.

Step4: Understand potential - energy concepts for question 3

Potential energy is stored energy that can do work and might be used later, and it can be changed into kinetic energy. So the correct statements for question 3 are A, B, C, D.

Step5: Recall elastic - potential - energy concept for question 4

The elastic potential energy of a rubber band depends on the amount it is stretched. A smaller - diameter cylinder will stretch the rubber band more. Among the options, the 5 - cm diameter cylinder will stretch the 10 - cm rubber band the most. So the answer to question 4 is A.

Answer:

1. C. speed and mass
2. C. 750 J
3. A. It can do work., B. It is stored energy., C. It might be used later., D. It can be changed into kinetic energy.
4. A. 5 cm