Answer:
- <em>The energy put into a machine or device to make it work is named</em> <u>work input.</u>
Explanation:
<em>Machines </em>are devices to perform tasks with less effort or more easily. They can either increase the force applied or change the direction of the force or permit to apply the force at a distance.
The law of conservation of energy states that the energy is neither created nor destroyed, but when the machines do <em>work</em> some energy is dissipated in the form of heat, light or sound, due, mainly to friction.
In consequence, the <em>work output</em> is less than the <em>work input</em>.
A measure of energy use is efficiency. The efficiency is the ratio of the work output to the work input.
Answer:
after 38.8 years it will double
correct option is D 38.8 years
Explanation:
given data
population grows rate = 1.8%
to find out
how many years will it take to double
solution
we consider here initial population is x
so after 1 year population will be = (100% + 1.8% ) x = 1.018 x
and after n year population will be = 
so it will double
2x =
take log both side
log 2 = n log (1.018)
n = 
n = 38.853
so after 38.8 years it will double
correct option is D 38.8 years
Explanation:
i think C . it is twice the size of the object
This relationship is called commensalism.
Answer:
F = 800 [N]
Explanation:
To be able to calculate this problem we must use the principle of momentum before and after the impact of the hammer.
We must summarize that after the impact the hammer does not move, therefore its speed is zero. In this way, we can propose the following equation.
ΣPbefore = ΣPafter
where:
m₁ = mass of the hammer = 0.15 [m/s]
v₁ = velocity of the hammer = 8 [m/s]
F = force [N] (units of Newtons)
t = time = 0.0015 [s]
v₂ = velocity of the hammer after the impact = 0
![(0.15*8)-(F*0.0015) = (0.15*0)\\F*0.0015 = 0.15*8\\F = 1.2/(0.0015)\\F = 800 [N]](https://tex.z-dn.net/?f=%280.15%2A8%29-%28F%2A0.0015%29%20%3D%20%280.15%2A0%29%5C%5CF%2A0.0015%20%3D%200.15%2A8%5C%5CF%20%3D%201.2%2F%280.0015%29%5C%5CF%20%3D%20800%20%5BN%5D)
Note: The force is taken as negative since it is exerted by the nail on the hammer and this force is directed in the opposite direction to the movement of the hammer.
