Answer:
Option (c).
Explanation:
An object when when projected at an angle, will have some horizontal velocity and vertical velocity such that,

is the angle of projection
The horizontal component of the projectile remains the same because there is no horizontal motion. Vertical component changes at every point.
As a projectile falls, vertical velocity increases in magnitude, horizontal velocity stays the same
.
Answer:
a). Maximum Length L=0.929m
b). T=0.83 Hz or 1.2s
c). Longer, the effortless waling T=2.1 Hz or t=0.475s
d). t=1.2s V=0.774 
t=0.475s V=1.95 
Explanation:
Length legs=L=1.1m
angle=50
the step that give the person forms a triangle whose two sides are known and the angle that forms between them, then using trigonometry as the image
Divide the original triangle in two and form a right triangle so the angle is 25 and the L is hypotenuse and the opposite is the step length
a).


Length of the step
L=0.464m*2
L=0.928m
b).
period=T

c).

The period is the inverse of the time of the motion so, the T1 is faster that the T because

d).
The speed is the relation between the distance with time so:

Answer:
chemical potential of a species is energy that can be absorbed or released due to a change of the particle number of the given species, e.g. in a chemical reaction or phase transition.
Explanation:
Answer:
The helicopter was deformed and destroyed in the inelastic collision.
Explanation:
- When two object collide there exist two way of colliding: elastic collision and inelastic collision.
- Two terms are considered during the collision: kinetic energy and momentum.
- If both of these terms are conserved in any collision then there is no significant loss of property, this is called as elastic collision.
- If only momentum is conserved but kinetic energy is converted into other forms then it is inelastic collision. In inelastic collision, the energy is lost in the form of vibration, sound etc. causing the damage to colliding object.
- Hence the deformation of helicopter was due to inelastic collision.