I’m guessing b because hydrogen is in your room and maybe eliminate to o but it also can be D
my final is: B!
Answer:
answer is C
Explanation:
acceleration is rate of changing velocity in a time
A) The vertical component of velocity v is taking the rock to a height
Vertical component =
The time taken to reach maximum height =
So total time of rocks flight =
Range of rock is due to the horizontal component of velocity =
Range =
=
Maximum height =
=
Since range = maximum height
We have
So when angle of projection is
range is equal to maximum height reached.
b) We have range =
=
Maximum of range is reached when
Maximum range =
c) For range to be equal to maximum height only condition is
, it does not depend upon acceleration due to gravity and velocity. That angle is a constant.
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
==>