No, wushu is not kung fu. The term kung fu （功夫（gong fu, kung fu)) is synonymous with Bruce Lee and for a very good reason. When Bruce Lee became popular with Western audiences in television and movies, he used the phrase to describe his martial arts. People misinterpreted this to mean that kung fu was martial arts; that kung fu was the Chinese style of punching and kicking.
So what is kung fu? Kung fu means the amount of time and energy one dedicates to learning a skill and it can refer to any area such as medicine, cooking, writing, art, or sports. For instance, one could say that Chef Wolfgang Puck expends a considerable amount of kung fu to create his signature tasty dishes. In the case of Bruce Lee, we should say that he had acquired an amazing amount of kung fu which helped him become the legend he is.