Answer:
Second projectile is 1.4 times faster than first projectile.
Explanation:
By linear momentum conservation
Pi = Pf
m x U + M x 0 = (m + M) x V

Now Since this projectile + pendulum system rises to height 'h', So using energy conservation:
KEi + PEi = KEf + PEf
PEi = 0, at reference point
KEf = 0, Speed of system zero at height 'h'

PEf = (m + M) g h
So,


So from above value of V
Initial velocity of projectile =U

Now Since mass of projectile and pendulum are constant, So Initial velocity of projectile is proportional to the square root of height swung by pendulum.
Which means



U₂ = 1.41 U₁
Therefore we can say that ,Second projectile is 1.4 times faster than first projectile.
The correct answer to the question is C i.e C represents the friction from air resistance.
EXPLANATION:
Before coming into any conclusion, first we have to understand friction.
The friction is the opposing force which acts tangentially between two bodies in contact when there is a relative motion between them.
The air resistance is that frictional force which is provided by the air to the moving body through it. Hence, the friction from air resistance will be directed opposite to the motion of the body.
In the given diagram, the airplane is going horizontally. The force A acts in forward direction while force C acts in backward direction. The forces B and D are acting vertically. There is no motion in vertical direction. Hence, the net force of A and C will cause the airplane to move.
As the plane is moving along the direction of A, the frictional force must act along the direction of C.
Answer:
Part of that kinetic energy created by moving of particles in object is transformed to heat that can be measured by thermometer.
Explanation:
By moving object creates kinematic energy, that is true. In object itself small particles are moving and creating kinetic energy as well. Part of that kinetic energy created by moving of particles in object is transformed to heat that can be measured by thermometer.
Same thing is that when you run or exercise your body temperature is raising(because of moving ).
When you sit your body does not raise temperature.
Answer:

Explanation:
As we know that the resultant of two vectors is given as

here we know that



now we have



True, according to the Kinetic Molecular Theory.