Final answer:
To determine at what time two objects, one falling from a height of 15 m and the other launched upward from the ground to a height of 60 m, cross paths, we can use the concept of projectile motion. The object falling takes about 1.77 s to hit the ground, and the object launched upward takes about 3.19 s to reach the height of 60 m. Therefore, the two objects will cross paths at approximately 1.77 s after the object falling is released.
Step-by-step explanation:
To determine at what time two objects, one falling from a height of 15 m and the other launched upward from the ground to a height of 60 m, cross paths, we can use the concept of projectile motion. When an object is launched upward or dropped from a height, it follows a parabolic path. The time at which the two objects cross paths can be determined by comparing their vertical positions at different times.
Let's assume that the object falling from a height of 15 m takes time 't' to hit the ground. We can use the equation h = ut + (1/2)gt^2, where h is the vertical displacement, u is the initial velocity, g is the acceleration due to gravity, and t is the time. For the object falling, h = 15 m, u = 0 m/s, and g = 9.8 m/s^2. Solving the equation for t, we get t = √(2h/g) = √(2*15/9.8) ≈ 1.77 s.
Now, for the object launched upward, let's assume it takes time 'T' to reach a height of 60 m. Since it is launched upward, its initial velocity, u = 0 m/s, and g = -9.8 m/s^2 (negative due to the opposite direction of motion). Using the same equation as before, h = 60 m, u = 0 m/s, and g = -9.8 m/s^2, we can solve for time 'T'. We get T = √(2h/g) = √(2*60/-9.8) ≈ 3.19 s.
Therefore, the two objects will cross paths at approximately 1.77 s after the object falling from a height of 15 m is released.