Answer with Explanation:
We are given that
Initial speed=
a.
Final velocity of ball=

g is negative because the ball is going against to gravity.




Using the formula


a.The ball rise upto height 18.4 m
b.It take 1.94 s to reach its highest point.
c.Initial velocity=0,s=18.4 m







Using the formula

Answer:
Commutator is a ring which reverse the direction of current in AC circuit so that the coil connected to it will continuous to move in the same direction.
Explanation:
In motors there exist a coil which is rotated due to torque of magnetic field when current flow through it. Since AC current is used to run the motor so we know that AC current changes its direction after half cycle.
So here commutator plays an important role to reverse the direction of current after every half cycle so that the current goes in same direction always into the coil.
This will produce a constant direction torque on the coil so that it will rotate in same sense always.
So commutator role is to provide same direction current to the coil by reversing its direction after every half cycle
Type into google: " water cycle" and this comes up.... put it in to your own words. This is very easy.
the cycle of processes by which water circulates between the earth's oceans, atmosphere, and land, involving precipitation as rain and snow, drainage in streams and rivers, and return to the atmosphere by evaporation and transpiration.
In solids, particles or atom are very closely arranged compared to gasses. When these particles are arranged in such proximity, vibrations from sound are very easily transmitted from one particle to another in the solid. Hence, the sound vibrations can travel through the solid medium more quickly than through a gas medium.
Speed of sound also depends on its frequency and the wavelength.
Explanation:
m = mass of burrito thrown by the student = 0.5 kg
a = acceleration of the burrito thrown by the student = 3 m/s²
F = force applied by the student on the burrito = ?
According to newton's second law , the net force on an object is the product of its mass and acceleration. it is given as
F = ma
inserting the values
F = (0.5) (3)
F = 1.5 N
hence the net force on the burrito comes out to be 1.5 N