Answer:
Explanation:
Given
Initial speed is u=V
Maximum height of Pebble is H
Deriving maximum height of Pebble and considering motion in vertical direction

where v=final velocity
u=initial velocity
a=acceleration
s=Displacement
Final velocity will be zero at maximum height


i.e. maximum height is dependent on square of initial velocity
for twice the height

on comparing
To solve this problem we will apply the concept of frequency in a string from the nodes, the tension, the linear density and the length of the string, that is,

Here
n = Number of node
T = Tension
= Linear density
L = Length
Replacing the values in the frequency and value of n is one for fundamental overtone



Similarly plug in 2 for n for first overtone and determine the value of frequency



Similarly plug in 3 for n for first overtone and determine the value of frequency



Answer:
55N
Explanation:
Using Newton's second law of motion:
F=ma
Force=mass × acceleration
F=25×2.2
F=55N
So 55 Newtons are needed
Answer:
14.4kJ
Explanation:
Work = Force x distance
W × h = mgh
Given that,
mass m, = 59.5kg
acceleration due to gravity = 9.8m/s^2
height ,h = 16.2cm
convert to m is 0.162m
How much work = m x g x h
height is 0.162 x 152 steps
h = 24.624m
work = 59.5 x 9.8 x 24.624
= 14,358.25Joule
= 14.4kJ