first we make a U turn and travel towards home in t = 20 s
so the distance of home from initial position is
Now after picking up the book we travel back with speed 20 m/s
so again after t = 20 s the displacement is given as
so the net displacement is given as
so it will be displaced by total displacement 200 m
Answer:
D all of the above
Explanation:
electricity moves easily through all of them and none of them prevent the flow of electricity
To solve this problem it is necessary to apply the equations related to the conservation of momentum.
This definition can be expressed as
Where
= Mass of each object
= Initial Velocity of each object
= Final velocity
Rearranging the equation to find the final velocity we have,
Our values are given as
Replacing we have,
Therefore the final velocity is 6.5m/s
We can use the law of conservation of energy to solve the problem.
The total mechanical energy of the system at any moment of the motion is:
where U is the potential energy and K the kinetic energy.
At the beginning of the motion, the ball starts from the ground so its altitude is h=0 and therefore its potential energy U is zero. So, the mechanical energy is just kinetic energy:
When the ball reaches the maximum altitude of its flight, it starts to go down again, so its speed at that moment is zero: v=0. So, its kinetic energy at the top is zero. So the total mechanical energy is just potential energy:
But the mechanical energy must be conserved, Ef=Ei, so we have
and so, the potential energy at the top of the flight is
