Choose the correct answer: A. Mechanical energy is conserved if, (a) the acting
ID: 1624528 • Letter: C
Question
Choose the correct answer: A. Mechanical energy is conserved if, (a) the acting force is a conservative force (b) the acting force is a gravitational force (c) the acting force is any type of force B. Mechanical energy cannot be conserved if the acting force is the drag force (True, False) C. Momentum cannot be conserved if the acting force is the drag force (True, False) D. If you increase the acting time of a collision the impact force increases (True, False) E. Neglecting air resistance, a projectile will encounter no change of its x-component of its velocity (True, False)Explanation / Answer
2) answer) option a) the acting force is a conservative force
Reason : total mechanical energy of a system remains constant when the forces acting are conservative forces
B) false
Reason : drag is non conservative force , so mechanical energy is not conserved
C) false
Reason : since external force is acting, momentum is not conserved
D) true
Reason : impulse = force*time = F*(t)
If time increases, then impulse increases
E) true
Reason : x component of velocity is given by
Vx = Vcos, here is angle at which projectile is projected
So it doesn't change