Answer:
B
Explanation:
because, convection is the transfer of heat between fluid substances/materials
Answer
given,
height of Alpe d'Huez = 1100-m
time = 37.5 min
mass of the rider and his bike = 65 Kg
the metabolic power to ride = 700 W
U = m g y
U = 65 x 9.8 x 1100
U = 700700 J
since efficiency is 25%





b) 

P = 1245.68 W
Answer:
part (a) 
part (b) N = 79.61 rev
part (c) 
Explanation:
Given,
- Initial speed of the wheel =

- total time taken = t = 20.0 sec
part (a)
Let
be the angular acceleration of the wheel.
Wheel is finally at the rest. Hence the final angular speed of the wheel is 0.

part (b)
Let
be the total angular displacement of the wheel from initial position till the rest.

We know, 1 revolution =
rad
Let N be the number of revolution covered by the wheel.

Hence the 79.61 revolution is covered by the wheel in the 20 sec.
part (c)
Given,
- Mass of the pole = m = 4 kg
- Length of the pole = L = 2.5 m
- Angle of the pole with the horizontal axis =

Now the center of mass of the pole = 
Weight component of the pole perpendicular to the center of mass = 

When K = 0, the motion's turning points take place. Think about frictionless one-dimensional motion in the x-direction. So whenever Etotal = U, K(x) = 0 and v = 0. (x).
<h3>How to describe friction</h3>
friction is the resistance to a thing moving or rolling over another solid object. Although frictional forces can be advantageous, such as the traction required to walk without slipping, they also provide a significant amount of resistance to motion.
<h3>What leads to friction?</h3>
Because of the imperfections on the two surfaces in contact, friction is produced. Small imperfections can be found on even the smoothest surfaces, and when two surfaces interact with one another, they cause friction.
To know more about friction visit:
brainly.com/question/13000653
#SPJ4
Answer:
Explanation:
The <u>centripetal acceleration</u>
of an object moving in a uniform circular path is given by the following equation:
(1)
Where:
is the tangential velocity
is the radius of the circle
On the other hand, the tangential velocity is expressed as:
(2)
Where
is the angular velocity, which can be found knowing the child makes 5 revolutions in 13.4s:
(3)
Substituting (3) in (2):
(4)
(5)
Substituting (5) in (1):
(6)
Finally: