A ball is thrown vertically upwards with a speed of 20 m/s. How high will it go

A ball is thrown vertically upwards with a speed of 20 m/s. How high will it go before it starts to fall back down? (g = 10 m/s²)

A ball is thrown vertically upwards with a speed of 20 m/s. How high will it go before it starts to fall back down? (g = 10 m/s²)

Correct Answer: 20 m

Step 1: Identify the initial speed (u) of the ball, which is 20 m/s.
Step 2: Identify the final speed (v) of the ball at the highest point, which is 0 m/s (it stops before falling back down).
Step 3: Identify the acceleration (a) due to gravity, which is -10 m/s² (negative because it acts downwards).
Step 4: Use the formula v² = u² + 2as to find the height (s).
Step 5: Substitute the values into the formula: 0 = (20)² + 2 * (-10) * s.
Step 6: Simplify the equation: 0 = 400 - 20s.
Step 7: Rearrange the equation to solve for s: 20s = 400.
Step 8: Divide both sides by 20 to find s: s = 400 / 20.
Step 9: Calculate the value: s = 20 m.

Kinematics – The question tests the understanding of kinematic equations, specifically how to apply them to motion under constant acceleration.
Projectile Motion – It assesses knowledge of vertical motion and the effects of gravity on an object thrown upwards.