Answer:
Explanation:
a ) The motion is one dimensional , so motion is along x - axis , starting from origin ( 0 , 0 )
b ) Initial velocity is 18.5 m /s when boat is situated at origin . When he displaces by 250 m along x axis and his position is ( 250 , 0 ) along x axis , his velocity becomes 36 m /s . Both his velocity and acceleration is along x - axis.
c ) Initial velocity vi = 18.5 m /s
final velocity vf = 36 m/s
Displacement x = 250 m
Acceleration a = ?
Most appropriate formula is given below .
vf² = vi² + 2 a x
2ax = vf² - vi²
x = ( vf² - vi² ) / 2 a
d )
Putting the given values
36² - 18.5² / 2 x 250
= 1296 - 342.25 / 500
= 1.9 m /s².
f ) Time interval t = ?
Required formula
vf = vi + at
t = (vf - vi ) / a
Putting the values
t = (30 - 18.5) / 1.9
= 6.05 second .
Answer:
To achieve the velocity of 40 m/sec height will become 4 times
Explanation:
We have given initially truck is at rest and attains a speed of 20 m/sec
Let the mass of the truck is m
At the top of the hill potential energy is mgh and kinetic energy is 
So total energy at the top of the hill 
At the bottom of the hill kinetic energy is equal to and potential energy will be 0
So total energy at the bottom of the hill is equal to 
Form energy conservation 
, for v = 20 m/sec
Squaring both side
h = 20.408 m
Now if velocity is 0 m/sec
h = 81.63 m
So we can see that to achieve the velocity of 40 m/sec height will become 4 times
Your question has no context, nobody’s going to be able to answer it.
Answer:
b) the refracted ray has an angle of 90 degrees
Explanation:
The angle of incidence is measured with respect to the normal separation of the media. The critical angle for total internal reflection occurs is:
Here 
and 
are the refractive index of the mediums. This equation is an application of Snell's law, for the case where the refracted ray has an angle of 
.
