Answer:
(a) 5.7 s
(b) 39 m/s
Explanation:
(a) u = 18 m/s
At the maximum height, the final velocity of ball is zero. lte teh time taken by the ball to go from 50 m height to maximum height is t.
use first equation of motion.
v = u + g t
0 = 18 - 10 x t
t = 1.8 s
Let the maximum height attained by the ball when it thrown from 50 m height is h'.
Use third equation of motion
v^2 = u^2 + 2 g h'
0 = 18^2 - 2 x 10 x h'
h' = 16.2 m
Total height from the ground H = h + h' = 50 + 16.2 = 76.2 m
Let t' be the time taken by the ball to hit the ground as it falls from maximum height.
use third equation of motion
H = ut + 1/2 x g t'^2
76.2 = 0 + 1/2 x 10 x t'^2
t' = 3.9 s
Total time taken by the ball to hit the ground = T = t + t' = 1.8 + 3.9 = 5.7 s
(b) Let v be the velocity with which the ball strikes the ground.
v^2 = u^2 + 2 g H
v^2 = 0 + 2 x 10 x 76.2
v = 39 m/s
Answer: Geologists study rocks to find clues to Earth's formation. Evidence from rocks and fossils allows us to understand the evolution of life on Earth.
Answer:
Decreases.
Explanation:
Electric potential energy is the potential energy which is associated with the configuration of points charge in a system and it is the result of conservative coulomb force.
When the negatively charge ion is at the position of the negative probe than its potential energy is positive when it is move towards the positive probe it's potential energy becomes negative due to the negative ion.
Therefore, potential energy is decreases when negative charge ion moves through the water from negative probe to positive probe.
Answer:
P = 96 J
Explanation:
Given that,
Weight of the book, W = mg = 8 N
It is placed at a height of 12 m
We need to find the potential energy of the book. The potential energy of an object is given by the formula as follows :
E = mgh
mg = Weight
So, the potential energy of the book is 96 J.
