Answer:
Explanation:
a ) starting from rest , so u = o and initial kinetic energy = 0 .
Let mass of the skier = m
Kinetic energy gained = potential energy lost
= mgh = mg l sinθ
= m x 9.8 x 70 x sin 30
= 343 m
Total kinetic energy at the base = 343 m + 0 = 343 m .
b )
In this case initial kinetic energy = 1/2 m v²
= .5 x m x 2.5²
= 3.125 m
Total kinetic energy at the base
= 3.125 m + 343 m
= 346.125 m
c ) It is not surprising as energy gained due to gravitational force by the earth is enormous . So component of energy gained due to gravitational force far exceeds the initial kinetic energy . Still in a competitive event , the fractional initial kinetic energy may be the deciding factor .
If the corner is rounded and is perfectly circular, then the acceleration is centripetal and is always directed toward the center.
Answer:
(a) 
(b) 
(c) 
Explanation:
Given that,
(a) An electron accelerated from rest through a potential difference of 100 V. The De Broglie wavelength in terms of potential difference is given by :

Where
m and e are the mass of and charge on an electron
On solving,

V = 100 V


(b) V = 1 kV = 1000 V



(c) If 


Hence, this is the required solution.
Answer:
C.) The Distance DH = 1.5 lambda
Explanation:
This statement C.) is false, because it does not count as the 1.5 wavelength, it is less than 1 wavelength.