Answer:
e) 120m/s
Explanation:
When the ball reaches its highest point, its velocity becomes zero, meaning
.
where 
is the initial velocity.
Solving for 
we get
which is the time it takes the ball to reach the highest point.
Now, after the ball has reached its highest point, it turns around and falls downwards. After time 
since it had reached the highest point, the ball has traveled downwards and the velocity 
it has gained is
,
and we are told that this is twice the initial velocity ; therefore,
which gives
Thus, the total time taken to reach velocity 
is
This 
, we are told, is 36 seconds; therefore,
and solving for we get:
which from the options given is choice e.
Because of symmetry electric field component in the x axis cancels out. Now just use electric field formula and slap that sine of theta cause you want the vertical component of electric field and multiply that by two since there’s two charges. I’ve shown my work. Hope it helps✌
Answer:
Explanation:
Given
time taken 
Speed acquired in 2 sec 
Here initial velocity is zero 
acceleration is the rate of change of velocity in a given time
Distance travel in this time
where
s=displacement
u=initial velocity
a=acceleration
t=time
so Jet Plane travels a distance of 42 m in 2 s
The answer is C!! 100 kilometers per hour is an average speed.
Answer:
Explanation:
Let the angle between the first polariser and the second polariser axis is θ.
By using of law of Malus
(a)
Let the intensity of light coming out from the first polariser is I'
.... (1)
Now the angle between the transmission axis of the second and the third polariser is 90 - θ. Let the intensity of light coming out from the third polariser is I''.
By the law of Malus
So,
(b)
Now differentiate with respect to θ.
