First, we must find the vertical distance traveled upwards by the ball due to the throw. For this, we will use the formula:
2as = v² - u²
Because the final velocity v is 0 in such cases
s = -u²/2a; because both u and a are downwards, the negative sign cancels
s = 14.5² / 2*9.81
s = 10.72 meters
Next, to find the time taken to reach the ground, we need the height above the ground. This is:
45 + 10.72 = 55.72 m
We will use the formula
s = ut + 0.5at²
to find the time taken with the initial velocity u = 0.
55.72 = 0.5 * 9.81 * t²
t = 3.37 seconds
Answer: 7.5 rev/s
Explanation:
We are given the angular velocity 
a helicopter's main rotor blades:
However, we are asked to express this in the International Systrm (SI) units. In this sense, the SI unit for time is second (
):
Answer:
D. Tidal energy is replaced naturally by the Moon's gravity.
Explanation:
The reason tidal energy is considered a renewable energy resource is that Tidal energy is replaced naturally by the Moon's gravity. The Moon's gravity creates bulges on the side of Earth that is closest and farthest from the Moon. These bulges also pull water causing high tides in those areas. As the Earth rotates these areas experience low tide while the areas that had low tide now experience high tide. This constant shift creates tidal energy every day, which is replenished naturally.
The figure shown above is series combination as the two resistors (bulb) are there which are then connected to the battery
so i conclude from the above options given the option is B
hope it helps
Answer:
C) steel turning to rust in salt air
Explanation:
The missing options are:
A) ice melting to form liquid water
B) water boiling to form steam
C) steel turning to rust in salt air
D) sugar dissolving into hot coffee
In a chemical change the atoms of the reacting compounds are reordered forming new compounds. In a chemical change, new compounds appear, but in a physical change not.
Then, change of states like ice melting and water boiling are not chemical changes.
During steel rust, components of steel, like iron, are oxidized, that is, reacts with oxygen forming oxides.
The dissolution of sugar into hot coffee is a physical change in which sugar molecules get further apart in the coffee, but they don't change.
