Answer:
Incomplete question
Check attachment for the given diagram
Explanation:
Given that,
Initial Velocity of drum
u=3m/s
Distance travelled before coming to rest is 6m
Since it comes to rest, then, the final velocity is 0m/s
v=3m/s
Using equation of motion to calculate the linear acceleration or tangential acceleration
v²=u²+2as
0²=3²+2×a×6
0=9+12a
12a=-9
Then, a=-9/12
a=-0.75m/s²
The negative sign shows that the cylinder is decelerating.
Then, a=0.75m/s²
So, using the relationship between linear acceleration and angular acceleration.
a=αr
Where
a is linear acceleration
α is angular acceleration
And r is radius
α=a/r
From the diagram r=250mm=0.25m
Then,
α=0.75/0.25
α =3rad/sec²
The angular acceleration is =3rad/s²
b. Time take to come to rest
Using equation of motion
v=u+at
0=3-0.75t
0.75t=3
Then, t=3/0.75
t=4 secs
The time take to come to rest is 4s
Answer:
2188 years
Explanation:
given,
see level rising at the rate = 3.2 mm/yr
height of the sea level to rise = 7 m
time it will take rise 7 m = ?
we know,
1 m = 1000 mm
1 mm = 0.001 m
rate of increase of rate = 0.0032 m/year
time taken to rise = 
= 2187.5 years
Now, time taken by the sea level to rise 7 m is equal to 2188 years.
Answer:
Explanation:
Bohr's energy expression is as follows
E_n = 13.6 z² /n² where z is atomic no and n is principal quantum no of the atom .
z for helium is 2 and for ionised atom is 5 . Let energy of n₁ level of He is equal to energy level n₂ of ionised atom
so
13.6 x 2² / n₁² = 13.6 x 5² / n₂²
n₁ / n₂ = 2/5 , ie 2nd energy level of He matches 5 th energy level of ionised atom .
For quantum numbers less than or equal to 9 , If we take n₁ = 8 for He
Putting it in the equation above
2² / 8² = 5² / n₂²
n₂ = 5 x 8 / 2
= 20 .
energy
= - 13.6 x2² / 8²
= - 0.85 eV .
Answer:
Density of body = 0.25g/cc
Explanation:
Given:
Volume submerged in water = 3/4
Find:
Density Of Body
Computation:
Density of body = fraction of body in liquid x density of water
Density of body = [1-3/4]1
Density of body = 0.25g/cc
The correct option is B.
Nuclear fission and fusion are two different types of nuclear reactions, through which energy may be obtained. Nuclear fission involves the splitting of a molecule into two different part in order to generate energy while nuclear fusion reaction involves the joining together of two elements in other to form one product. Nuclear fission generate much radioactive waste than nuclear fusion. The radioactive waste that is obtainable during nuclear fusion is less than 1% of that produce by nuclear fission.