Answer:20.82 m
Explanation:
Given
distance between wall and launcher=5 m
initial velocity=30 m/s
Launching angle
Height of wall=12 m
maximum height by ball
h=22.95 m
y=4.72 m
so ball will strike with wall
and for perfect restitution final velocity of ball will be same as the horizontal velocity before its impact, only direction will be opposite and vertical velocity will be zero
thus it seems as if someone throw the ball with horizontal velocity of 30cos45 from a height of 4.72
Time required to cover 4.72 m
t=0.981 s
Horizontal distance traveled in this time
R=20.82 m
The solution for the problem is:
1 Watt = 1 Joule per second
1 Watt*second = 1 Joule
a Kilowatt is 1,000 Watts
an hour is 60 seconds times 60 minutes or 3,600 seconds
a Kilowatt * hour is 1,000 Watts in 3,600 seconds
15 W*h = 15,000 Watt*hour = 15,000 Watt * 3,600 seconds = 54,000,000
Watt*second
54,000,000 Watt*second = ? Joules
54,000,000 Joules / second = 54,000,000 Watts
Answer:
y = 20.38 [m]
Explanation:
In order to solve these problems, we must use the following kinematics equation.
where:
Vf = final velocity = 0
Vi = initial velocity = 72 [km/h]
g = gravity acceleration = 9.81 [m/s^2]
y = vertical elevation [m]
We need to convert [km/h] to [m/s]
![72[\frac{km}{h}]*[\frac{1h}{3600s}]*[\frac{1000m}{1km} ] = 20 [m/s]](https://tex.z-dn.net/?f=72%5B%5Cfrac%7Bkm%7D%7Bh%7D%5D%2A%5B%5Cfrac%7B1h%7D%7B3600s%7D%5D%2A%5B%5Cfrac%7B1000m%7D%7B1km%7D%20%5D%20%3D%2020%20%5Bm%2Fs%5D)
Note: the negative sign of the equation means that the acceleration acts in the opposite direction to the movement of the body. And the final speed is zero, because when the body reaches the maximum height, the Stone does not move its speed has been reduced to its entirety.
0 = (20)^2 - (2*9.81*y)
20^2 = 2*9.81*y
y = 20.38 [m]
Kepler noticed an imaginary line drawn from a planet to the Sun and this line swept out an equal area of space in equal times, If we then draw a triangle out from the Sun to a planet’s position at one point in time, it is notice that the area doesn't change even after the planet has left the original position say like after 2 to 3days or 2hours. So to have same area of triangle means that the the planet move faster when that are closer to the sun and slowly when they are far from the sun.
This led to Kepler's law of orbital motion.
First Law: Planetary orbits are elliptical with the sun at a focus.
Second Law: The radius vector from the sun to a planet sweeps equal areas in equal times.
Third Law: The ratio of the square of the period of revolution and the cube of the ellipse semi-major axis is the same for all planets.
It is this Kepler's law that makes Newton to come up with his own laws on how planet moves the way they do.
Answer:
c. Velocity
Explanation:
Velocity is a measure of change of position of the body with time. Change of position means the distance traveled by the object in a given interval of time but in a particular direction.
We know that speed is given as the distance traveled over a given time interval without taking into account the direction of motion. So, the magnitude of velocity is same as its speed. Velocity, being a vector quantity, has both magnitude and direction.
Therefore, the <u>velocity</u> of an object consists of its speed and direction.
