| 1) What are the x- and y-coordinates of the projectile at: |
(a) t = 0 s? (b) t = 2.4 s? (c) t = 4.8 s? |
(a) 0,0 m (b) 20.4 m, 28 m (c) 41 m, 0 (approximate due to cursor sensitivity) |
| 2) What is the significance of the x and y-coordinates at these times? |
| The x- and y- coordinates represent the position of the projectile. |
| 3) (a) Using the cursor, determine the difference in height of the two projectiles at points A and B. |
| Height of B = 33 m and height of A = 23.2 m. Δy = 32 m - 23.2 m = 9.8 m. |
| (b) Confirm your results by using the appropriate kinematics equation(s). |
| For
B: Δy = vi * Δt = 23.5 m/ |
| For
A: Δy = vi * Δt + 1/2*g*Δt2 =
23.5 m/ |
| Δy = 32.9 m - 23.3 m = 9.6 m |
| 4) Is there any air resistance acting on the projectile? How do you know? |
| Air resistance is a not a factor in the animation. Air resistance depends on two factors: size and speed of |
| the projectile. The size of the projectile is constant and the speed is variable. Air resistance would be more |
| pronounced in the descent of the projectile because it is increasing speed on the way down. The |
| animation clearly shows the parabola is symmetrical with both halves being identical. |
| 5) How do the upward and downward velocities compare? Support your answer. |
| Because air resistance is not a factor, the only force acting on the projectile is Fw, the weight of the |
| projectile. The same net force will provide the same acceleration (-g) and the magnitude of the velocities |
| will be equal. |
| 6) How do the initial and final horizontal velocities of the projectile compare? Justify your answer. |
| The horizontal acceleration of the projectile is zero in the absence of any horizontal forces. The horizontal |
| motion of the projectile is an example of Newton's 1st Law and it follows that both velocities are equal. |