To find the kinetic energy (Ek) of the ball after 1 second, we need to calculate its velocity at that time.
When the ball is thrown vertically upwards, it will experience a constant acceleration due to gravity, which is approximately 9.8 m/s^2. The initial velocity is 20 m/s in the upward direction.
To find the final velocity after 1 second, we can use the kinematic equation:
v = u + at
where: v = final velocity u = initial velocity a = acceleration t = time
Substituting the values into the equation:
v = 20 m/s + (-9.8 m/s^2) * 1 s v = 20 m/s - 9.8 m/s^2 v = 10.2 m/s (upward)
Now that we have the final velocity, we can calculate the kinetic energy (Ek) using the formula:
Ek = (1/2) * m * v^2
where: Ek = kinetic energy m = mass v = velocity
Substituting the values into the equation:
Ek = (1/2) * 0.05 kg * (10.2 m/s)^2 Ek = (1/2) * 0.05 kg * 104.04 m^2/s^2 Ek = 2.601 J
Therefore, the kinetic energy of the ball after 1 second is approximately 2.601 Joules.