Question:

A ball is thrown upward with an initial velocity of 20 m/s. Assuming no air resistance, calculate the displacement of the ball after 2 seconds.

Answer:

To solve this problem, we can use the kinematic equation for displacement:

d = v0t + (1/2)at^2

Where:

• d represents the displacement
• v0 represents the initial velocity
• t represents the time
• a represents the acceleration

Given:

• v0 = 20 m/s
• t = 2 s
• a = -9.8 m/s^2 (since we are considering the downward direction as negative)

Let's substitute these values in the equation:

d = v0t + (1/2)at^2

d = (20 m/s)(2 s) + (1/2)(-9.8 m/s^2)(2 s)^2

d = 40 m + (-9.8 m/s^2)(4 s^2)

d = 40 m - 39.2 m

d = 0.8 m

Therefore, the displacement of the ball after 2 seconds is 0.8 meters.