Answer:
(a) Workdone = -27601.9J
(b) Average required power = 1314.4W
Explanation:
Mass of hoop,m =40kg
Radius of hoop, r=0.810m
Initial angular velocity Winitial=438rev/min
Wfinal=0
t= 21.0s
Rotation inertia of the hoop around its central axis I= mr²
I= 40 ×0.810²
I=26.24kg.m²
The change in kinetic energy =K. E final - K. E initail
Change in K. E =1/2I(Wfinal² -Winitial²)
Change in K. E = 1/2 ×26.24[0-(438×2π/60)²]
Change in K. E= -27601.9J
(a) Change in Kinetic energy = Workdone
W= 27601.9J( since work is done on hook)
(b) average required power = W/t
=27601.9/21 =1314.4W
Answer: c Delta
Explanation:
A delta is a landform created by deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more rarely) another river that cannot carry away the supplied sediment.
Hope this helps!!
Answer: 25 Ohms
Explanation:
From this question, the following parameters are given:
Voltage V = 1.5 v
Current I = 0.03A
From Ohm's law;
V = IR
Where R = resultant resistance of the two resistors.
Substitute V and I into the formula and make resultant R the subject of formula.
1.5 = 0.03 × R
R = 1.5/0.03
R = 50 Ohms
From the question, it is given that Thr two equal resistors are connected in series.
R = R1 + R2
But R1 = R2
50 = 2R1
R1 = 50/2
R1 = 25
R1 = R2 = 25 Ohms
Therefore, the resistors must each have a value of 25 Ohms
