ANS:B - 0.50 s

To solve this problem, we can analyze the motion of the water jet using basic principles of physics. We'll consider the motion in the vertical direction. Given:

• Initial velocity (u) = 9.81 m/s (upward)
• Angle of elevation (θ) = 30°

We need to find the time taken (t) for the water jet to reach the highest point. The initial velocity can be split into horizontal and vertical components:

• Ux=ucosθ
• Uy=usinθ

Where:

• ux​ is the horizontal component of velocity.
• uy​ is the vertical component of velocity.

At the highest point, the vertical component of velocity becomes 0 because the water momentarily stops before falling back down due to gravity. We can use the equation of motion to find the time taken to reach the highest point: uy​=usinθ−gt Where:

• g is the acceleration due to gravity (approximately 9.81 m/s^2).

At the highest point, uy​=0. So, we have: 0=usinθ−gt Solving for t: t=usinθ​/g Substituting the given values: t=9.81×sin⁡(30∘) / 9.81 =9.81×0.5 / 9.81 = 0.5  Therefore, the time taken to reach the highest point is 0.5s. Thus, the correct option is 0.50s.