Question

What are the kinematic assumptions for objects thrown vertically upwards?

1) The object is thrown vertically upwards with an initial velocity of zero.
2) The object experiences a constant acceleration due to gravity.
3) The object reaches its maximum height and then falls back downwards.
4) The object follows a parabolic trajectory.

Answer 1

The kinematic assumptions for vertically thrown objects are that they are thrown with an initial velocity, experience constant acceleration due to gravity, reach zero velocity at maximum height, and then descend. It's incorrect to assume the initial velocity is zero or that the trajectory is parabolic, as that requires a horizontal component.

Step-by-step explanation:

The kinematic assumptions for objects thrown vertically upwards include the following:

1. The object is thrown vertically upwards with a certain initial velocity, not necessarily zero (this is the velocity at the moment it leaves the thrower's hand).
2. Throughout its flight, the object experiences a constant acceleration due to gravity, which is approximately 9.81 m/s2 downward on Earth.
3. When the object reaches its maximum height, its velocity is zero. This is the turning point of the motion where the object stops moving upward and begins its descent.
4. Despite option 4 provided in the question, the motion of the object is not parabolic if it's thrown straight upwards; instead, it follows a straight line path. Parabolic trajectories involve both vertical and horizontal components, which isn't the case for vertical throws.

Error in option 1: The initial velocity is not zero, it's the velocity imparted to the object when it is thrown.

Error in option 4: The trajectory is not parabolic for purely vertical motion. Parabolic trajectories occur only when there is initial horizontal velocity (e.g., in projectile motion).