When the height of an object doubles, its potential energy also doubles. This is because potential energy is directly proportional to the height of the object. As the height increases, the object gains more potential energy due to its increased distance from the ground. Therefore, doubling the height results in a doubling of the potential energy of the object. **

Online commerce refers to the buying and selling of goods and services over the internet, while retail commerce refers to the traditional brick-and-mortar stores where customers can physically visit and make purchases. Online commerce offers the convenience of shopping from anywhere at any time, while retail commerce provides the opportunity for customers to see, touch, and try products before making a purchase. Online commerce often involves lower overhead costs and can reach a wider audience, while retail commerce provides a more personalized and immediate shopping experience. **

When there are 2 cats, the number of paws doubles. Each cat has 4 paws, so when there are 2 cats, there are a total of 8 paws. Additionally, the amount of fur and dander in the household may also double with the presence of 2 cats. **

Online shopping has certainly had an impact on retail stores, as it has changed consumer behavior and shopping habits. Many traditional brick-and-mortar stores have struggled to compete with the convenience and variety offered by online shopping. However, it's important to note that online shopping has also created new opportunities for retailers to reach customers and expand their businesses. While some retail stores have closed due to the rise of online shopping, others have adapted by offering online options and enhancing their in-store experiences to remain competitive. Overall, online shopping has transformed the retail landscape, but it hasn't necessarily destroyed retail stores entirely. **

There is no women's doubles event in luge because the sport is traditionally competed in singles or individual events. Luge is a high-speed, technical sport that requires precise coordination and control, making it challenging for two athletes to compete together on the same sled. Additionally, the physical demands of luge may make it difficult for two athletes to navigate the course effectively as a team. As a result, luge has remained a solo event in both men's and women's competitions. **

When rolling two dice, if both dice show the same number, it is called rolling doubles. In most games, rolling doubles gives the player a special advantage, such as being able to move their game piece twice the number shown on the dice. However, some games may have different rules for rolling doubles, so it's important to check the specific rules of the game being played. Overall, rolling doubles is usually a lucky outcome that can give the player an edge in the game. **

Yes, there have been instances where actor stunt doubles have died during filming. For example, in 2017, a stunt double for the TV show "The Walking Dead" died after suffering injuries during a stunt. Additionally, in 2017, a stunt double for the movie "Deadpool 2" died while performing a motorcycle stunt. These tragic incidents highlight the risks and dangers that stunt performers face in their line of work. **

No, one cannot play tennis doubles alone. Tennis doubles requires two players on each team, so playing alone would not be possible. Doubles is a team sport that involves cooperation and coordination between two players, and it is not feasible for one person to cover the entire court and effectively compete against a pair of opponents. **