Answer:
659.01W
Explanation:
The cab has a mass of 1250 kg, the weight of the cab represented by Wc will be
Wc = mass of the cab × acceleration due to gravity in m/s²
Wc = 1250 × 9.81 = 12262.5 N
but the counter weight of the elevator represented by We = mass × acceleration due to gravity = 995 × 9.81 = 9760.95 N
Net weight = weight of the cab - counter weight of the elevator = Wc - We = 12262.5 - 9760.95 = 2501.55 N
the motor of the elevator will have to provide this in form of work
work done by the elevator to lift the cab to height of 49 m = net weight × distance (height) = 2501.55 × 49m
power provided by the motor of the elevator = workdone by the motor / time in seconds
Power = (2501.55 × 49) ÷ ( 3.1 × 60 seconds) = 659.01 W
Answer:
C
Explanation:
To calculate adjacent of triangle use
where 45 is the hypotenuse, and a is the adjacent side (horizontal component)
then round to 38.2
Answer:
K = 588.3 N/m
Explanation:
From a forces diagram, and knowing that for the maximum value of K, the crate will try to rebound back up (Friction force will point downward):
Fe - Ff - W*sin(22) = 0 Replacing Fe = K*X and then solving for X:
By conservation of energy:
Replacing our previous value for X and solving the equation for K, we get maximum value to prevent the crate from rebound:
K = 588.3 N/m
Answer:
22kj
Explanation:
set h = 0 at the end of slide.
final height is -12m
initial condition will be Ui = 0
Ki = 1/2mv² = 1/2 x 61 x (27)² = 22234.5J
Final condition is Ui = mgh = 61 x 9.8 x -12 = -7173J
Ki = 1/2mv²
Ki= 1/2 x 61 x (16)² = 7808J
conservation energy says that
Ui + Ki = Uf +Kf +ΔEth
so ΔEth = Ui + Ki - Uf - Kf
ΔEth = 22234.5 - 7808 + 7173
ΔEth = 21600J
ΔEth =22Kj
