A because the toaster converts electrical energy into heat energy and, after the bread has been heated for sufficient time, toasts pop out, ready to be buttered. And converting means transforming.
The mirror formula for curved mirrors is:

where
f is the focal length of the mirror

is the distance of the object from the mirror

is the distance of the image from the mirror
The sign convention that should be used in order to find the correct values is the following:
-

: positive if the mirror is concave, negative if the mirror is convex
-

: positive if the image is real (located on the same side of the object), negative if it is virtual (located on the opposite side of the mirror)
Answer:
As the tines of the tuning fork vibrate at their own natural frequency, they created sound waves that impinge upon the opening of the resonance tube. These impinging sound waves produced by the tuning fork force air inside of the resonance tube to vibrate at the same frequency.
Given:
Mass(m)=75kg
Height (h) =100m
v(velocity)=60m/s
a(g)=9.8m/s^2(since it is a free falling object)
Now we know that
v=u+at
We know that
Potential energy=mgh
Where m is the mass
g is the acceleration due to gravity
h is the height above the ground
Substituting the above values we get
Potential energy=75 x 9.8 x 100
=73500N
Now kinetic energy =1/2mv^2
Where m is the mass
v is the velocity
Kinetic energy= 1/2 (75x60 x 60)
Kinetic energy=135000N
Now mechanical energy=
Kinetic energy+ Potential energy
Substituting the values in the above formula we get
Mechanical energy= 73500+135000
=208500N
we Know that gravitational field strength(g) at a point on a planet is equal to gravitational force exerted per unit mass placed at that point.
It Means,
g=F/m
Here,
g=gravitational field strength
F=Gravitational force
m=Mass
Case A
planet force =10 and mass= .5
g1=F/m
g1=10/.5
=100/5
g1=20m/s
case B
F=30 and m=2
therefore g2=30/2
g2=15m/s^2
case C
F=45 and m=3
g3=45/3
=15m/s^2
case D
g4=60/6
g4=10m/s^2
from above results it is clear that the gravitational field strength of planet D is minimum which is 10m/s^2 and gravitational field strength of planet A is maximum which is 20m/s^2