I think they decrease echo and reduce noise, they do this by either absorbing vibrations or by scattering the sound so that echoes arrive at different times rather than reverberating as a standing wave. An echo is a reflection of a sound that arrives at the listener with a delay after the direct sound. The delay is usually proportional to the distance of the reflecting surface from the source and the listener.
A. cleaning up after environmental disasters
Explanation:
Load=800N
Effort=200N
1. Mechanical Advantage = LOAD/EFFORT
= 800N/200N
= 4
2 Velocity Ratio = no. Of pulleys =5
3. Efficiency = Mechanical advantage / velocity ratio × 100%
= (4/5)×100%
=80%
4. output work= load×load distance
= 800N × 5m
= 4 × 1000J
5. Efficiency = (output work/input work) ×100%
Or, 80% = (4000J/input work) ×100%
Or, 80%/100% = 4000J/inputwork
Or, 4/5 = 4000J/inputwork
Or, input work =4000J × 5/4
Input work = 5×1000J
I hope it helped! ;-)
Answer:
0.0334N
Explanation:
Given parameters:
M1 = 5 x 10⁶kg
M2 = 1 x 10⁶kg
Distance = 100m
Unknown:
Gravitational force = ?
Solution:
To solve this problem, we use the Newton's law of universal gravitation.
Fg = 
G is the universal gravitation constant
m is the mass
r is the distance
Fg = 
= 0.0334N
