Power can be calculate through the equation,
Power = Force x velocity
It should be noted that velocity is calculated by dividing displacement by time. Thus, from the given in this item we can calculate for the power.
Power = (120 lb) x (12 ft/9 s)
<em> </em><span><em>Power = 160 lb.ft/s</em></span>
You should select Choice-4 .
D. all of these
all of these use electricity
Hope I helped!
Answer:
Explanation:
First of all we shall find the velocity at equilibrium point of mass 1.2 kg .
It will be ω A , where ω is angular frequency and A is amplitude .
ω = √ ( k / m )
= √ (170 / 1.2 )
= 11.90 rad /s
amplitude A = .045 m
velocity at middle point ( maximum velocity ) = 11.9 x .045 m /s
= .5355 m /s
At middle point , no force acts so we can apply law of conservation of momentum
m₁ v₁ = ( m₁ + m₂ ) v
1.2 x .5355 = ( 1.2 + .48 ) x v
v = .3825 m /s
= 38.25 cm /s
Let new amplitude be A₁ .
1/2 m v² = 1/2 k A₁²
( 1.2 + .48 ) x v² = 170 x A₁²
( 1.2 + .48 ) x .3825² = 170 x A₁²
A₁ = .0379 m
New amplitude is .0379 m
1) B. Energy is the ability to do work
2) C. Energy is conserved, it just goes from one form to another.
3) Work = Force x displacement
= 300 x 100 = 30,000 Joules
4) leaning a brick because no displacement is taking place.
5) They change the amount/strength or direction of the force needed.
6) Less force is needed and applied over a longer distance.
7) Heat is the flow of thermal energy from one object to another.
