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Projectile motion: Two objects are kicked upward at different angles...

  • #1

Homework Statement


Two objects are kicked upward at different angles. Object A travels a greater horizontal distance than object B. Both reach the same maximum height. Which of the following statements about the objects are true? You may select more than one.
1.Object A is in the air for a longer time than object B.

2.Both objects are in the air for the same amount of time.

3.The initial velocities of both objects have the same magnitude.

4.The vertical component of B's initial velocity is larger than the vertical component of A's initial velocity.

5.The vertical component of their initial velocities are the same.

6.The magnitude of object A's initial velocity is larger than the magnitude of object B's initial velocity.

7. The initial velocities of the objects have the same magnitude.

8.Object B is in the air for a longer time than object A.


Homework Equations



The Attempt at a Solution


I thought statements 2,3,4 and 7 were right.
 
Last edited by a moderator:

Answers and Replies

  • #2
ehild
Homework Helper
15,427
1,827

Homework Statement


Two objects are kicked upward at different angles. Object A travels a greater horizontal distance than object B. Both reach the same maximum height. Which of the following statements about the objects are true? You may select more than one.
1.Object A is in the air for a longer time than object B.

2.Both objects are in the air for the same amount of time.

3.The initial velocities of both objects have the same magnitude.

4.The vertical component of B's initial velocity is larger than the vertical component of A's initial velocity.

5.The vertical component of their initial velocities are the same.

6.The magnitude of object A's initial velocity is larger than the magnitude of object B's initial velocity.

7. The initial velocities of the objects have the same magnitude.

8.Object B is in the air for a longer time than object A.


Homework Equations



The Attempt at a Solution


I thought statements 2,3,4 and 7 were right. [/B]
Explain why do you think 2, 3, 4 , 7 are right.
 
  • #3
DaveC426913
Gold Member
18,648
2,117
The key, I think, is to consider the vertical component separate from the horizontal component, as if they are unrelated.

If you pretended to view this experiment directly along the line of the trajectory, and with only one eye open, you would witness only the vertical components.
This is particularly useful for examining option 2.

The rest follow.
 
  • #4
osilmag
Gold Member
125
30
y=-1/2gt^2 + v(initial)t + y0

If I use that equation and both are in the air for the same amount of time and they reach the same height, would four still be true?
 
  • #5
358
108
y=-1/2gt^2 + v(initial)t + y0
Specific to that equation, what is the direction component of v(initial) ?
 
Last edited:
  • #6
osilmag
Gold Member
125
30
Specific to that equation, what is the direction component of v(initial) ?
The vertical direction.

It's a rhetorical question.
 

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