Hi Guys,
Are my reasoning's for these questions okay? The question is related to projectile motion.
Question: A parcel is dropped from a height of 500m from a helicopter travelling at a speed of 20m/s.
(a) Describe the effects of air resistance on:
(i) the horizontal component of the motion of the parcel.
(ii) the vertical component of motion of the parcel.
(i)
- Air resistance of an object increases when the velocity of the object increases as well(Air Resistance ∝ Velocity).
- As the object descends more and more, the air resistance would be applied to a larger effect on the horizontal component of motion.
- The horizontal component of motion(its velocity) would decrease in value as it decelerates due to the horizontal net force becoming more and more non zero.
(ii)
- Air resistance of an object increases when the velocity of the object increases as well(Air Resistance ∝ Velocity).
- Unlike horizontal motion, the velocity in the vertical component would increase in value as initially, the velocity in the vertical component would be 0m/s due to it being dropped from rest.
- As the objects descends closer to the ground, the velocity in the vertical component of the object gets bigger due to the non zero net force. However, even though the velocity is getting greater, air resistance slows down the acceleration of the object meaning the vertical component of the velocity as it hits the ground won't be as high of a value as it would if air resistance was not involved at all(was negligible).
(b) Which of the horizontal or vertical components of the motion of the parcel is likely to experience the greater air resistance during:
(i) the first 2 seconds of its fall
(ii) the final 2 seconds of its fall?
(i)
My Answer: Horizontal Component.
- This is due to air resistance in the horizontal direction causing the horizontal velocity to decrease.
- The velocity in the vertical direction would still increase, even with the presence of air resistance involved.
(ii) My Answer: Vertical Component.
- This is due to air resistance causing the vertical velocity to accelerate slowly(not as much as it would if air resistance was not involved).
- Since in the final 2 seconds where the horizontal velocity would already be decelerating closer and closer to 0m/s, the effect in which air resistance would be applied to the horizontal component decreases as Air Resistance ∝ Velocity.
All replies would be much appreciated. Thanks
