Explanation and answer:
This problem is best answered by drawing a figure as a first step.
ABC is the scaffold.
A downward force of 500N is applied downwards at 1m from end A.
The weight of 800N is exerted by the scaffold uniformly distributed between A & C.
At A and C, ropes are attached to support the load.
Let Fc=tension in rope passing through C.
Take moments about A:
Fc = (500N * 1m +800N*(3+1)/2m / 4m
= (500 Nm + 1600Nm) / 4m
= 2100 Nm / 4m
= 525 N
Answer: a) 18670 W b) 25 hp
Explanation:
a)
Average power,
P = W/t
W= 0.5 MVf^2 - 0.5 MVo^2
Therefore P =( (0.5 x 112 x 34.5^2 ) - (0.5 x 112 x 0 ) ) / 3.57
P = 1.87 x 10^4 W
b)
Power in units of horsepower is
P = 1.87 x 10^4 / 745.7 = 25hp
The main formula is
a=2d/t^2, so we can deduce that <span><span>t^2=2d / a, and t=sqrt(2d/a)
</span>for a=</span>2(m/s^2), d=10 meters,
so t=sqrt(2x10/2)=sqrt(10) s
<span>A hockey puck is sliding on frictionless ice on an infinite hockey rink.
Its speed is 36 km/hour. How far does the puck slide in 10 seconds ?
(36 km/hr) x (1,000 m/km) x (1 hr/3600 sec) x (10sec) =
(36 x 1,000 x 10 / 3,600) meters = <em>100 meters</em>
What is the puck's speed in miles per hour ?
(36 km/hr) x (0.6214 mi/km) = <em>22.37 mi/hr
</em></span>