Question

A projectile is fired with a velocity $u$ making an angle $\theta$ with the horizontal. What is the magnitude of change in velocity when it is at the highest point -

• A. $u \cos \theta$
• B. $u$
• C. $u \sin \theta$
• D. $u \cos \theta - u$

Answer 1

Answer: (C)

$u \sin \theta$

Answer 2

The thing to note is when the projectile reaches it's highest point, it has lost all of its vertical velocity. The vertical velocity of this projectile is $u \sin \theta$ and since the projectile loses this velocity, it would have a difference of $u \sin \theta$.