Answer:
a. Planets move on elliptical orbits with the Sun at one focus.
Explanation:
Johannes Kepler was an astronomer who discovered that planets had elliptical orbits in the early 1600s (between 1609 and 1619).
The three (3) laws published by Kepler include;
I. The first law of planetary motion by Kepler states that, all the planets move in elliptical orbits around the Sun at a focus.
II. According to Kepler's second law of planetary motion, the speed of a planet is greatest when it is closest to the Sun.
Thus, the nearer (closer) a planet is to the Sun, the stronger would be the gravitational pull of the sun on the planet and consequently, the faster is the speed of the planet in terms motion.
III. The square of any planetary body's orbital period (P) is directly proportional to the cube of its orbit's semi-major axis.
Hence, one of Kepler's laws of planetary motion states that planets move on elliptical orbits with the Sun at one focus. This is his first law of planetary motion.
Answer:
21.21 m/s
Explanation:
Let KE₁ represent the initial kinetic energy.
Let v₁ represent the initial velocity.
Let KE₂ represent the final kinetic energy.
Let v₂ represent the final velocity.
Next, the data obtained from the question:
Initial velocity (v₁) = 15 m/s
Initial kinetic Energy (KE₁) = E
Final final energy (KE₂) = double the initial kinetic energy = 2E
Final velocity (v₂) =?
Thus, the velocity (v₂) with which the car we travel in order to double it's kinetic energy can be obtained as follow:
KE = ½mv²
NOTE: Mass (m) = constant (since we are considering the same car)
KE₁/v₁² = KE₂/v₂²
E /15² = 2E/v₂²
E/225 = 2E/v₂²
Cross multiply
E × v₂² = 225 × 2E
E × v₂² = 450E
Divide both side by E
v₂² = 450E /E
v₂² = 450
Take the square root of both side.
v₂ = √450
v₂ = 21.21 m/s
Therefore, the car will travel at 21.21 m/s in order to double it's kinetic energy.
Answer:
So percentage error will be 2 %
Explanation:
We have given initial value of acceleration due to gravity 
And final value of acceleration due to gravity 
We have to find the percentage error
We know that percentage error is given by 
So
%
Answer:Two early signs of dehydration are thirst and dark-coloured urine. This is the body's way of trying to increase water intake and decrease water loss.
Explanation: