<span>When you are in the way of a moving object and a collision is sure to occur, you are better off decreasing its momentum over time. Which is nothing but force.
mv/t = m.a = F
Fill the blank as: "Time"
Hope this helps!</span>
Its tangential speed is constant although its velocity is changing. As the object changes direction, it results in a changing of positive and negative signs of the velocity. Although, the magnitude of the velocity (speed) is not changing.
The angle of refraction would be further less