A) The stone moves along the vertical direction by unifom accelerated motion, with acceleration equal to g (gravitational acceleration), starting from initial position h above the ground and with initial velocity equal to zero. So, its vertical position follows the law:
b) The time the stone takes to reach the ground is the time t at which its vertical position y(t) becomes zero:
and if we solve it, we find
c) Since it is a uniform accelerated motion, the velocity of the stone at time t is given by
where the initial velocity is zero:
. The stone hits the ground at t=9.6 s, so its velocity at that time is
where the negative sign means it is directed downward.
d) In this case, since the initial velocity is not zero, the position at time t is given by
where
is the initial velocity.
The time the stone takes to reach the ground is the time t such that y(t)=0, so we have:
and by solving this equation, we find
Newton's 3rd law states that every action has an equal and opposite reaction. This means that if the astronaut throws his 50kg backpack in the direction in which he is drifting with enough force, he will propel himself back towards the spaceship
Answer:
Option A - the moment of inertia of the system decreases and the angular speed increases.
Explanation:
The moment of Inertia of merry- go-round spins is
I = + mr²
ζ = I
ζ =( + mr²)
= ζ / ( + mr²)
where is the angular speed
increases when the moment of inertia decreases
Therefore, it is true to say that the moment of inertia of the system decreases and the angular speed increases.