Answer :
Valid U values: 53 and 0. Invalid U values: 61, 106, 76, 49, 14, 47. Uₓ = -53, Uₓ = Ucos(0°).
The value of Uₓ (horizontal component of velocity) is given as -53. We need to determine which of the given values for U (initial velocity) could not be valid.
Since Uₓ = U × cos(θ), where θ is the angle of projection, we can calculate the possible values of U for each given value of Uₓ and θ = 0 (horizontal projection).
Given Uₓ = -53:
1. U = 61: Uₓ = 61 × cos(0°) = 61 × 1 = 61 (Not a valid choice)
2. U = 53: Uₓ = 53 × cos(0°) = 53 × 1 = 53 (Valid choice)
3. U = 106: Uₓ = 106 × cos(0°) = 106 × 1 = 106 (Not a valid choice)
4. U = 0: Uₓ = 0 × cos(0°) = 0 × 1 = 0 (Valid choice)
5. U = 76: Uₓ = 76 × cos(0°) = 76 × 1 = 76 (Not a valid choice)
6. U = 49: Uₓ = 49 × cos(0°) = 49 × 1 = 49 (Not a valid choice)
7. U = 14: Uₓ = 14 × cos(0°) = 14 × 1 = 14 (Not a valid choice)
8. U = 47: Uₓ = 47 × cos(0°) = 47 × 1 = 47 (Not a valid choice)
Based on the calculations, the following values of U could not be the value of U:
1. U = 61
3. U = 106
5. U = 76
6. U = 49
7. U = 14
8. U = 47
So, the valid choices for U are 53 and 0.
See more on angle of projection here:
https://brainly.com/question/28919403
#SPJ11
