Answer:
C
Explanation:
Newtons second law explains this the most because for every action their is an equal and opposite reaction. The reaction of you turning, causes the reaction of your whole body to turn with the bike.
The frequency doesn't change. If the wavespeed increases, then the wavelength must also increase ... It's just the distance the wave travels during each complete wiggle.
Answer:
(a) 
(b) 
(c) K.E. = 21.168 J
(d) 
Explanation:
Given:
- mass of a block, M = 3.6 kg
- initial velocity of the block,

- constant downward acceleration,

That a constant upward acceleration of
is applied in the presence of gravity.
∴
- height through which the block falls, d = 4.2 m
(a)
Force by the cord on the block,



∴Work by the cord on the block,


We take -ve sign because the direction of force and the displacement are opposite to each other.

(b)
Force on the block due to gravity:

∵the gravity is naturally a constant and we cannot change it


∴Work by the gravity on the block,



(c)
Kinetic energy of the block will be equal to the net work done i.e. sum of the two works.
mathematically:


K.E. = 21.168 J
(d)
From the equation of motion:

putting the respective values:

is the speed when the block has fallen 4.2 meters.
Answer:
0.04225 Nm
Explanation:
N = Force applied = 5 N
= Coefficient of static friction = 0.65
d = Diameter of knob = 1.3 cm
r = Radius of knob = 
Force is given by

When we multiply force and radius we get torque
Torque on thumb

Torque on forefinger

The total torque is given by

The most torque that exerted on the knob is 0.04225 Nm