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:1.84
Explanation:
Given
Humming bird travels 1.2 m along a straight line at height of 3.4 m
Now bird drops 1.4 m to hover in front of the flower
So bird net displacement is
displacement
displacement
=1.84
It is a gas. Gases can easily change volume and always fill the whole container.
<span>The time it takes for one wavelength to pass a fixed point is known as PERIOD.
In fact, the period is defined as the time it takes a wave to make one complete oscillation: since the wavelength is the distance between two consecutive points of the wave with same shape, it means that the time it takes for one wavelength to pass a fixed point in space is exactly the period.</span>
