Filmmakers need to resist the impulse to move the camera quickly from detail to detail for fear of boring the viewer, to frame the image for the sake of drama alone, to add music for fear of silence.
Retailers like them as they add a dash of colour and buzz to shops, and because they can squeeze more money out of each customer through impulse purchases.
零售商们喜欢促销，因为这样可以给商店带来一些生机，而且还能通过消费者的冲动购买榨取更多钱。
3
Add an instant force impulse to the rigidbody, using its mass.