Answer:
(A) 3.1 m/s
(B) 2.0 s
Explanation:
At the minimum speed, the force of gravity equals the centripetal force.
mg = m v² / r
v = √(gr)
v = √(9.8 m/s² × 1.0 m)
v = 3.1 m/s
The time is the circumference divided by the speed.
t = (2π × 1.0 m) / (3.1 m/s)
t = 2.0 s
Answer:
P = 4.5 watts
Explanation:
Given that,
EMF of the circuit, E = 3 volt
The resistance of the resistors, R = 2 ohms
We need to find the power of this circuit. The relation between power, emf and resistance is given by the formula as follows :

Substitute all the values,

So, the power of this circuit is equal to 4.5 watts.
Answer:
625 W
Explanation:
Applying
P = W/t.................... Equation 1
Where p = power, W = Work, t = time
But,
W = Force (F) × distance (d)
W = Fd........................ Equation 2
Substitute equation 2 into equation 1
P = Fd/t.................... Equation 3
From the question,
Given: F = 5000 N, d = 30 m, t = 4 munites = (4×60) seconds = 240 seconds
Substitute these values into equation 3
P = (5000×30)/240
P = 625 Watt
I think the correct answer from the choices listed above is option D. Scientific theories summarize patterns found in nature. Although, the statement scientific theories are never proven is somewhat true. They are either disproved or they are never disproved. Hope this answers the question.