Sagot :
a)The velocity of the object when it hits the ground will be 1.12 × 10⁵ m/sec
b) The time taken for the object to reach the ground will be 11.4 × 10³ sec.
What is projectile motion?
The motion of an item hurled or projected into the air, subject only to gravity's acceleration, is known as projectile motion.
The velocity in the x-direction;
[tex]\rm v_x = (vcos \theta)^2 +2gh \\\\ v_x = (50 cos 30)^2+ 2 \times 9.81 \times 4000 \\\\ v_x = 80355 m/sec[/tex]
Velocity in y-direction;
[tex]\rm v_ y = (vsin \theta)^2 + 2gh \\\\ v_ y = (25)^2+2 \times 9.81 \times 4000 \\\\ v_y =79105 \ m/sec[/tex]
The resultant velocity is found as 1.12 × 10⁵ m/sec.
The time taken to reach the ground is found as;
[tex]\rm v = u+gt \\\\ 1.12 \times 10^5 \ m/sec = 50 \ m/sec + 9.81 \times t \\\\ t = 11.4 \times 10^3 \ sec[/tex]
Hence, the velocity of the object when it hits the ground will be 1.12 × 10⁵ m/sec, and the time taken for the object to reach the ground will be 11.4 × 10³ sec.
To learn more about the projectile motion refer to the link
https://brainly.com/question/11049671
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