Answer: B
Explanation:
Given that an object of mass 2 kg starts from rest and is allowed to slide down a frictionless incline so that its height changes by 20 m.
The parameters given from the question are:
Mass M = 2kg
Height h = 20m
Let g = 9.8m/s^2
At the bottom of the incline plane, the object will experience maximum kinetic energy.
From conservative of energy, maximum K.K.E = maximum P.E
Maximum P.E = mgh
Maximum P.E = 2 × 9.8 × 20 = 392 J
But
K.E = 1/2mv^2
Substitute the values of energy and mass into the formula
392 = 1/2 × 2 × V^2
V^2 = 392
V = sqrt( 392 )
V = 19.8 m/s
V = 20 m/s approximately
NOTE: The strength of an electromagnet is directly proportional to not only the current but the number of windings. Doubling the number of windings doubles the strength of the magnet.
In spring mass system we know that angular frequency is given as
f = 8.38 Hz
now we know that speed of SHM at its extreme position is given by
here we know that
A = 17.5 cm
so maximum speed is 9.21 m/s
