K.E. = 1/2 mv²
K.E. is directly proportional to v^2
So, when K.E. increase by 2, K.E. increase by root. 2
v' = 1.41v
original v value was 3 so, final would be:
v' = 1.41*3 = 4.23
After round-off to it's tenth value, it will be:
v' = 4.2
So, option B is your answer!
Hope this helps!
Answer:
3.7 m/s
Explanation:
M = 444 kg
U = 5 m/s
m = 344 kg
u = - 5 m/s
Let the velocity of train is V and the car s v after the collision.
As the collision is elastic
By use of conservation of momentum
MU + mu = MV + mv
444 x 5 - 344 x 5 = 444 V + 344 v
500 = 444 V + 344 v
125 = 111 V + 86 v .... (1)
By using the formula of coefficient of restitution ( e = 1 for elastic collision)
-5 - 5 = V - v
V - v = - 10
v = V + 10
Substitute the value of v in equation (1)
125 = 111 V + 86 (V + 10)
125 = 197 V + 860
197 V = - 735
V = - 3.7 m/s
Thus, the speed of first car after collision is 3.7 m/s. negative sign shows that the direction is reverse as before the collision.
The phase of the Moon must be new, and the nodes of the Moon's orbit must be nearly aligned with Earth and the Sun.
<span>Vibration waves from earth quakes travel through the earth and have measurable speed. And the different temperatures and fluidity of the various regions of the mantle will change that speed and or reflect the vibration waves in different directions. With multiple vibration sensors around the world the time that it takes for vibrations to travel from one part of the world to another will tell you what is inside.</span>
Explanation:
the morning of the birthday party balloon filled with the 2.5 Litre of helium
temperature is 294kelvin
the party starts at the 4 p.m.
temperature rises 305 Kelvin.
the new volume = 4 litre.
At same temperature,
P
1
V
2
=P
2
V
2
(Boyle's law)
P
1
=10atm;P
2
=1atm
V
1
=4l=V
2
=8l
But while filling balloons from cylinder when pressure in cylinder becomes 1 atm then further filling is not possible (P
1
′
=9atm)
Let n be the number of balloons that can be filled.
∴P
1
′
V
1
=n(P
1
V
1
)
9×8=n(4×1)
n=
4
9×8
=18balloons
