Answer:
Option (c) : 20°C
Explanation:
T(final) = 500* 10 + 100*70/600 = 20°C
Answer:
x(t) = - 6 cos 2t
Explanation:
Force of spring = - kx
k= spring constant
x= distance traveled by compressing
But force = mass × acceleration
==> Force = m × d²x/dt²
===> md²x/dt² = -kx
==> md²x/dt² + kx=0 ------------------------(1)
Now Again, by Hook's law
Force = -kx
==> 960=-k × 400
==> -k =960 /4 =240 N/m
ignoring -ve sign k= 240 N/m
Put given data in eq (1)
We get
60d²x/dt² + 240x=0
==> d²x/dt² + 4x=0
General solution for this differential eq is;
x(t) = A cos 2t + B sin 2t ------------------------(2)
Now initially
position of mass spring
at time = 0 sec
x (0) = 0 m
initial velocity v= = dx/dt= 6m/s
from (2) we have;
dx/dt= -2Asin 2t +2B cost 2t = v(t) --- (3)
put t =0 and dx/dt = v(0) = -6 we get;
-2A sin 2(0)+2Bcos(0) =-6
==> 2B = -6
B= -3
Putting B = 3 in eq (2) and ignoring first term (because it is not possible to find value of A with given initial conditions) - we get
x(t) = - 6 cos 2t
==>
A classic puzzle...
She either kicked it at a wall <em>exactly</em><em /> 10 foot in front of her, where the ball rebounded off the wall.
Or, she kicked the ball straight up, vertically, at a <em>90 degree angle,</em> where due to the law of gravity, which states that anything that goes up must come down, when the soccer ball reaches exactly 10 feet, it falls back down.
(Note: This is nearly impossible to achieve -- exactly 10 feet.)
Answer:
I believe the answer would be C. point z
Answer:
Spaceship speed is 36000 km/h
So, in 1 hour spaceship travel 36000 km
Or we can say that in 60×60 second spaceship travel 36000 km
Therefore in 1 sec spaceship travel
=
= 10 km/s
