Answer:
D. Friction
Explanation:
Friction is a force that opposes motion. So a perpetual motion machine can never be built because it is impossible to eliminate frictional force. It can only be reduced
Answer:
The mass of the banana is m and it is at height h.
Applying the Law of Conservation of Energy
Total Energy before fall = Total Energy after fall
=
Here, total energy is the sum of kinetic energy and potential energy
+
=
+
(a)
When banana is at height h, it has
= 0 and
= mgh
and when it reaches the river, it has
= 1/2m
and
= 0
Putting the values in equation (a)
0 + mgh = 1/2m
+ 0
mgh = 1/2m
<em>cutting 'm' from both sides</em>
<em> </em>gh = 1/2
v = 
Hence, the velocity of banana before hitting the water is
v = 
Answer:
C) 2.44 × 106 N/C
Explanation:
The electric flux through a circular loop of wire is given by

where
E is the electric field
A is the cross-sectional area
is the angle between the direction of the electric field and the normal to A
The flux is maximum when
, so we are in this situation and therefore
, so we can write

Here we have:
is the flux
d = 0.626 m is the diameter of the coil, so the radius is
r = 0.313 m
and so the area is

And so, we can find the magnitude of the electric field:
