On Earth, the acceleration of gravity is 9.8 m/s² downward.
So any object with only gravity acting on it gains 9.8 m/s of
downward speed every second.
If the rock starts out moving upward at 10 m/s, then it will
continue upward for only (10/9.8) = 1.02 second, before
it stops rising and starts falling.
Its average speed during that time is (1/2) (10 + 0) = 5 m/s .
At an average speed of 5 m/s for 1.02 sec,
the rock rises
(5 m/s) x (1.02 sec) = 5.102 meters .
Answer:
Explanation:
velocity of first projectile after 3 s
v = u - gt
v = 49.4 - 9.8 x 3
= 20 m /s
Velocity of second projectile after 3 s after being dropped from rest
v = u + gt
= 0 + 9.8 x 3
= 29.4 m /s
They will be moving in opposite direction at the time of meeting , so their relative velocity
= 20 + 29.4 = 49.4 m /s
From the frame of reference of the first projectile, the velocity of the second projectile will be 49.4 m /s .
Explanation:
All living organisms metabolize. That is the definition of life. So jr answer is no animal or organism that does not consume food.
Answer:
a. It is constant the whole time the ball is in free-fall
Explanation:
If we divide the movement on its vertical and horizontal components, and we concentrate on the vertical component, let's call x-component, and analyze Newton's second's law:
with 
, 
the acceleration on horizontal direction and m the mass of the ball, because the only force acting on the object is gravity that is always vertical, there're not forces on the horizontal direction that means 
and by (1) that implies =0 there's not acceleration on horizontal direction.
Because acceleration is the rate at what velocity changes and there's no acceleration, there's no change in velocity, in other words velocity is constant on horizontal direction.
Answer: v = 20 m/s
Explanation: Solution:
Use the formula of Kinetic Energy and derive for v:
KE = 1/2 mv²
To find v:
v = √ 2 KE / m
= √ 2 ( 100000 J ) / 500 kg
= √ 400 m/s
= 20 m/s
