Keeping in mind that the conversion between calories and Joules is
we can write the conversion factor using the kilocalories:
The energy released in our problem is
so we can set a simple proportion to find its equivalent in kcal:
from which we find:
Answer:
Option d)
Solution:
As per the question:
Work done by farm hand, 
Force exerted, F' = 310 N
Angle, 
Now,
The component of force acting horizontally is F'cos
Also, we know that the work done is the dot or scalar product of force and the displacement in the direction of the force acting on an object.
Thus
d = 3.406 m = 3.4 m
Answer: Resistance = 
The approximate diameter of a penny is, <em>d</em> = 20 mm
thickness of penny is, <em>L = </em> 1.5×
mm
The area of penny along circular face is,
= 3.14×
m²
The resistivity of copper is <em>ρ</em> = 1.72 x 10-8 Ωm.
Resistance,
Answer:
980 J
Explanation:
The change in box's energy is equal to its change in gravitational potential energy:
where
m = 50 kg is the mass of the box
g = 9.8 m/s^2 is the acceleration due to gravity
is the change in height of the box
Substituting numbers, we find
I could be wrong, but I'm pretty sure it's 144kg.
