Answer:
a)W= - 47.19 J
b)47.19 J
Explanation:
Given that
Weight ,mg= 71.5 N
y= 1.84 m
H= 2.5
a)
The distance above the hand ,h= 2.5 - 1.84 m
h= 0.66 m
We know that gravitaional force act in the downward direction but the displacement is in upward direction that is why work done will be negative.
W= - m g h
W= -71.5 x 0.66 J
W= - 47.19 J
b)
The potential energy at initial position = m g y
The potential energy at final position = m g H
So change in the potential energy = m g H - m g y
= mg ( H- y)
=71.5 ( 2.5 - 1.84 ) = 47.19 J
Therefore change in the potential energy = 47.19 J
The observed differences in amplitudes are due to interference between the sound waves. The decrease in amplitude is due to destructive interference of the waves and the increase in amplitude is due to constructive interference.
Answer: well the time it takes to fall 100m is the same time it takes to travel 65m horizontally.
The time to fall vertically, t is sqrt(2d/g). [this comes from d = 1/2at^2]
so t = sqrt(2*100/9.8) = 4.52s.
The vertical speed at that time is g*t = 9.8*4.52 = 44.3m/s
The horizontal speed is the horizontal distance over the same 4.52s, = 65/4.52 = 14.4m/s.
so the final velocity is = sqrt(44.3^2 + 14.4^2) = 46.6m/s
Explanation: yes
Answer:
Friction = 2 N
Explanation:
F = ma
= .4 * 24.5 = 9.8 N net force 10 N by stick means Ffriction = 2 N