Answer: In all cases, gravitational potential energy, respect from a common reference level (street level for instance) is the same.
Explanation:
Gravitational potential energy, comes from the action of the gravitational field, which is a conservative one.
This means, that if someone does work against the field (for instance lifting a weight from the ground to a given height), and then drops the weight, the work done by the field will be exactly the same.
Otherwise, the object would have remaining energy after returning to the starting point, which would violate the laws of physics, specially Thermodynamic's 2nd Law.
For this reason, the gravitational potential energy only depends from the height, and is independent from the path taken to reach there.
Answer:
43.83
N
Explanation:
Given that,
The mass of an object, m = 34.4 kg
The coefficients of static and kinetic frictions for plastic on wood are 0.53 and 0.40, respectively.
The force of static friction,
The force of kinetic friction,
Net force acting on the object is :
F = 178.67-134.84
= 43.83 N
Hence, this is the required solution.
Answer & Explanation: Waste management are all activities and actions required to manage waste from its inception to its final disposal. There are several methods of managing waste with its strengths and weaknesses. The strengths include;
* It creates employment
* It keeps the environment clean
* The practice is highly lucrative
* It saves the earth and conserves energy
The weaknesses of the methods of waste management includes;
* The sites are often dangerous
* The process is mostly
* There is a need for global buy-in
* The resultant product had a short life
Answer:
4m/s
Explanation:
The motion is in downward direction, and the boat is moving with constant velocity, the position of the boat horizontally is 12m before the key fall.
The height difference "h"= ( y- y°)= 45 m
We can determine the needed time the key requires to reach the water using the expression from Newton's law
h= v(o) + 1/2 at^2
g= acceleration due to gravity= 9.8m/s^2
h= v(o) + 1/2 gt^2 -------------------------eqn*)
V(o)= 0 for the key= initial velocity
h= height that the key falls= 45m
If we substitute the above values into eqn(*) we have
We can make t^2 subject of the formula since v(0)= 0
t^2= h/(1/2 g)
= 45/(1/2× 9.8)
t^2= 45/4.9=9.18
t= √9.18
t=3.03 secs
Since the boat was moving with constant velocity,
Then Velocity= distance/ time
= 12/3.03
Velocity= 4m/s
Hence, the speed of the boat is 4m/s
True. Their immune system weakens and they stay sick until they die.
