Question

Problem 27d

Answer 1

Given information

Given a projectile is fired with an initial speed of   at an angle of   above the horizontal on a long flat firing range.

To determine the speed of the projectile  after firing.

Step-by-step explanation

Step 1.

After the object is released, it follows a parabolic path and undergoes projectile motion. Assuming that air resistance is negligible, kinematic equations for two dimensions can be used to calculate its final speed.

Recall that in this case of projectile motion, the initial velocity  can be resolved into its  and  components using the equations below.

   

where  is the angle the velocity vector makes with the horizontal.

Furthermore, the horizontal velocity remains constant all throughout the object's motion while the vertical velocity changes because of the downward acceleration with magnitude of  .

To get the speed of the object  after it was released, get the magnitudes of the horizontal and vertical velocities and combine them using the Pythagorean theorem.