Question

question 3 (2 points) listen when we throw a ball into the air, it will have no acceleration. it will keep moving at constant velocity. true false question 4 (2 points) listen two projectiles are thrown with the same initial speed, one at an angle a with respect to the level horizontal ground and the other at an angle of 90 degrees - a (for example, if one is thrown at 20 degrees, the other is thrown at 70 degrees). both projectiles strike the ground at the same distance from the projection point. are both projectiles in the air for the same length of time? yes no

Explanation:

Question 3

Step1: Consider gravitational force

When a ball is thrown into the air, the gravitational force acts on it. The acceleration due to gravity near the Earth's surface is approximately $g = 9.8\ m/s^{2}$ acting down - ward. So, it cannot move with constant velocity as there is an acceleration $a=-g$.

Question 4

Step1: Analyze time - of - flight formula

The time - of - flight formula for a projectile is $T=\frac{2v_{0}\sin\theta}{g}$, where $v_{0}$ is the initial velocity, $\theta$ is the angle of projection and $g$ is the acceleration due to gravity. If one projectile has an angle of projection $\theta_{1} = A$ and the other has $\theta_{2}=90 - A$, then $T_{1}=\frac{2v_{0}\sin A}{g}$ and $T_{2}=\frac{2v_{0}\sin(90 - A)}{g}=\frac{2v_{0}\cos A}{g}$. Since $\sin A
eq\cos A$ (except for $A = 45^{\circ}$), the times of flight are not the same.

Answer:

Question 3: False
Question 4: No