An astronaut on a distant planet wants to determine its acceleration due to gravity. The astronaut throws a rock straight up with a velocity of 19 m/s and measures a time of 24.4 s before the rock returns to his hand. What is the acceleration (magnitude and direction) due to gravity on this planet

1.56 m/s²

Explanation:

Projectile motion is a form of motion where an object moves in parabolic path (trajectory). Projectile motion only occurs when there is one force applied at the beginning on the trajectory, after which the only interference is from gravity.

The total time (time of flight) of an object is given by:

T = 2usinθ / g

where u is the initial velocity, θ is the angle with horizontal and g is the acceleration due to gravity

Since the astronaut throws a rock straight up, hence θ = 90°, u = 19 m/s, T = 24.4 s.

T = 2usinθ / g

Substituting:

24.4 = 2(19)(sin90)/g

g = 2(19)(sin90) / 24.4

g = 1.56 m/s²

c. newton's third law of motion