Answer:
4.6s
Explanation:
v=u+at
0=22.5+(-9.8)t
-22.5=-9.8t
t=-22.5/-9.8
t=2.295 s
The total time will double
2.295×2=4.59s
=4.6s
Answer:

Explanation:
ΣF=ma
The two forces at play are the force applied and the force due to friction. As they are opposing forces set the direction being pushed as the positive in the x direction. the equation you come out with is 60 - 15=(15)A (we know mass to be 15kg). Solve for 3 m/s^2.
Elements are identified by the nuclei of the atoms of which they are made. For example, an atom having six protons in its nucleus is carbon, and one having 26 protons is iron. ... Heavy elements can be formed from light ones by nuclear fusion reactions; these are nuclear reactions in which atomic nuclei merge together. This is how they are formed
The velocity of the car at the bottom of the hill=19.8 m/s
mass= 100 kg
height= h=20 m
Velocity at the bottom=V
Using the law of conservation of energy
potential energy at top = kinetic energy at the bottom
m g h= 1/2 m v²
g h= 1/2 v²
9.8 (20)=1/2 V²
V=19.8 m/s
Thus the velocity of car at the bottom of hill=19.8 m/s