Answer:
Explanation:
Velocity of sound in air at 20 degree = 343 m/s
Velocity of sound in water at 20 degree = 1470 m/s
Time taken in to and fro movement in air
=( 2 x 10) / 343 = 0.0583 s
Rest of the time is
.171 - .0583 = .1127 s
This time is taken to cover distance in water. If d be the depth of lake
2d / velocity = time taken
2 d / 1470 = .1127
d = 82.83 m
Answer:
1) p₀ = 45000 N / s
, p₀ '= 1800
, b) I = -45000 N s
, I = 1800 Ns
Explanation:
Impulse equals the change in momentum
I = Δp
1) the initial moment of the car
p₀ = M v
p₀ = 1500 30
p₀ = 45000 N / s
the change at the moment is
Δp = 45000
because the end the car is stopped
moment of the person
P₀ ’= m v
p₀ '= 60 30
p₀ '= 1800
D₀ '= 1800
2) of the momentum change impulse ratio
car
I = Δp
I = -45000 N s
person
I = Δpo '
I = 1800 Ns
3) the object that give the momentum to stop the wall motoring
The person is stopped by the impulse given by the car
a) This area is the one that absorbs most of the vehicle impulse
be) If using a safety painter, the time during which the greater force will act, therefore the lessons decrease
c) The air bag helps reduction in the speed of the person relatively quickly.
Nuclear fusion reactions convert protons into helium; thus, becoming the source of all energy radiated by the sun.
Answer: Option D
<u>Explanation:</u>
Nuclear fusion reaction is one among the two nuclear reactions in which the atoms nucleus interact with each other to produce the products. In nuclear fusion, two smaller atoms react together to form a new atom with bigger size.
So large amount of energy is required to start the nuclear fusion reaction. The fusion reactions mostly occurs in stars. The illumination in Stars even the Sun is due to nuclear fusion reaction occurring with the atoms present in them.
Mostly the energy radiated by Sun is due to the protons-protons chain reaction. In this chain reaction, the protons get converted into helium due to nuclear fusion reaction, thus becoming the source of all energy radiated by the Sun.
