Answer:
The initial speed of the ball is 30 m/s.
Explanation:
It can be assumed that the ball is thrown at an angle of 45 degrees to the ground. The ball lands 90 m away. We need to find the initial speed of the ball. We know that the horizontal distance covered by the projectile is called its range. It is given by :

u is the initial speed of the ball.


v = 29.69 m/s
or
v = 30 m/s
So, the initial speed of the ball is 30 m/s. Hence, this is the required solution.
Answer:
Explanation:
A ball is thrown vertically upward with a certain Kinetic Energy in the absence of air resistance and while returning it experiences air resistance.
Air resistance causes the ball to lose its kinetic energy as it provides resistance which will convert some of its kinetic energy to heat energy.
So in a way total energy is conserved but not kinetic energy as some portion of it is lost in the form of heat.
Answer:
The frequency of a wave is measured in Hz (hertz)
<span>Convection means the movement happens inside a fluid
by the cause of too much heat and lesser density to rise, and also the colder
cause denser materials to sink.
Thus, Solid cannot undergo convection because the molecules inside the solid
are closer and can hardly move unlike liquid.
So, when the temperature got hotter or colder, the molecules on solid will only
vibrate and not convert.
Therefore, this concludes that the solid do not undergo convection rather
conduction of heat.</span>
The kinetic energy bc the energy is independent of the gravitational acceleration, and it depends only on the speed and mass. So the last answer