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:
+1 ion
Explanation:
Alkali metals are metals that are found in Group I of the periodic table. Their electronic configuration is such that their valence shell in grounds state is always holding only one electron which they always lose when reacting with non-metals. A loss in an electron makes the atom electrically imbalanced and hence becoming a +1 ion.
Answer:
The horizontal component of its velocity remains constant and the vertical component of its acceleration is equal to -g.
Explanation:
This is because, the projectile has both vertical and horizontal components of velocity. But, its vertical component of velocity changes as the object moves whereas, its horizontal component of velocity remains constant.
Also, the projectile has only vertical component of acceleration and no horizontal component of acceleration since, its horizontal component of velocity remains constant. Thus, no change in the horizontal component of velocity.
The vertical component of acceleration is equal to -g since, the weight is the only vertical force acting on it.
So, <u>the horizontal component of its velocity remains constant and the vertical component of its acceleration is equal to -g.</u>
Answer:
There is no change, unless your mass is somehow at the quantum level, at which the concept of half-life breaks down.
Half life is a property of the specific radioactive isotope...NOT of the initial sample's mass.
1. Learners are engaged by scientifically oriented questions.
2. Learners give priority to evidence, allowing them to develop and
evaluate explanations that address scientifically-oriented questions.
3. earners formulate explanations form evidence to address scientifically
oriented question
4. Learners evaluate their explanations in light of alternative explanations,
particularly those reflecting scientific understanding.
5. Learners communicate and justify their proposed explanations.
