Answer:
-1.09m/sec^2
Explanation:
Acceleration= (Vf-Vi)/Time
=12-54.8
= -42.8
= -42.8/39
=-1.09
-ve sign is due to recoil of train
as it suddenly hits brakes.
Answer:
The kinetic energy is 86.6 zepto joules.
Explanation:
Given that,
Number of orbit n =5
We know that,
Bohr's radius for hydrogen atom is

Now, put the value of n in the formula of radius


We need to calculate the kinetic energy
Using formula of kinetic energy

Put the value into the formula


We know that,

The kinetic energy is


Hence, The kinetic energy is 86.6 zepto joules.
As the core collapses, the outer layers of the star are expelled. A planetary nebula is formed by the outer layers. The core remains as a white dwarf and eventually cools to become a black dwarf. ... Like low-mass stars, high-mass stars are born in nebulae and evolve and live in the Main Sequence
hydrogen shell burning - outer layers swell. Red Giant Branch - helium ash core compresses - increased hydrogen shell burning. First Dredge Up - expanding atmosphere cools star - stirs carbon, nitrogen and oxygen upward - star heats up.
Answer:
1. a 
b 
c 
2. 
Explanation:
a). The work done by the tension is:




b). The work done potential of gravity




c). The work done by the normal force



2. The increase in thermal energy is:





Answer:
a = 0.45 m/s²
Explanation:
The given question is ''Calculate the acceleration that produces a force of 40 N on a body with 88 kg of mass".
Given that,
Force, F = 40 N
Mass of the body, m = 88 kg
The net force acting on the body is given by :
F = ma
Where
a is the acceleration of the body

So, the required acceleration is 0.45 m/s².