C.energy
The law of conservation of energy says that energy can neither be created nor destroyed.
Answer:
Explanation:
a) Using the equation of motion
S = ut + 1/2gt²
S is the distance of fall
g is the acceleration due to gravity
t is the time taken
Given S = 12.0m, g = 9.81m/s^2, un= 0m/s
12 = 0+1/2(9.81)t²
12 = 4.905t²²²
t² = 12/4.905
t² = 2.446
t = √2.446
t = 1.56secs
b) To determine how fast is the frog falling at this point, we need to calculate the speed of the frog. Using the equaton v = u+gt
v = 0+9.81(1.56)
v = 15.34m/s
Hence the frog is falling at the rate of 15.34m/s
<span> planetary satellites vary greatly in size, from very small, to some that are larger than some planets.</span>
Answer: part a: 19.62m
part b: 19.62 m/s
part a: 2.83 secs
Explanation:If the air resistance is ignored then the swimmer experience free fall under gravity hence
u=0
a=9.81 m/s2
t=2 secs
s=h
Part b
Part c
now we have h=2*19.62=39.24
Let's start with the concept of momentum. What is it? Linear momentum in physics is mathematically written as a product of mass and velocity of an object. Now let us suppose a body of mass m is moving in an inertial frame of reference with velocity v. Consider the fact that no external force is acting on the system. The momentum of this body is given by mv, where m is the mass and v is its velocity. In case of simple real world problems not delving into the realms of relativity, mass is a conserved quantity and it cannot be zero. Hence the velocity of the body must be zero and hence the momentum.
However, photons are considered to have a rest mass zero.
However note the point carefully "rest mass". A body in motion cannot have mass to be zero.
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