Answer:
The value is 
Explanation:
From the question we are told that
The horizontal speed is 
The horizontal distance is 
Generally the time taken by the hot magma in air before landing is mathematically represented as

=> 
=> 
Generally the initial vertical velocity of the magma when it was lunched is

Then the final velocity of the magma when it hits the ground is mathematically represented s

Here the negative sign mean that the direction of the velocity is towards the negative y -axis
So

=> 
I think your answer would be DDT, but don't hold me to it
Answer:
(a) 40.6 degree
Explanation:
When refraction takes place from slab to water, the critical angle is 60 degree.
Use Snell's law
refractive index of water with respect to slab



μs = 1.536
Now for slab air interface, the critical angle is C.


1 / 1.536 = Sin C
C = 40.6 degree
The roller coaster is moving in a circular path, so the force that must be computed is the centripetal force. The centripetal force is the force acting on an object undergoing circular motion and is directed towards the center of the circular path. This is computed using:
F = mv²/r
F = (500 * 18²) / 12
F = 13,500 N
Now, at the bottom of the track, the track is also supporting the weight of the car and its passengers, which is:
W = mg
W = 500 * 9.81
W = 4,905 N
The total reactive force exerted by the track to counter the centripetal force and the weight of the car is:
F = 13,500 + 4,905
F = 18,405 Newtons