If the boat's velocity is 18m/sec relative to the water in the river and not the shore, it would need to be added the river speed of 2.5m/sec to get a total of 20.5m/sec. The 20.5m/sec would then be the total velocity of the boat relative to the shore. From personal experience, I know that when one runs with the tide, one is adding the tide flow speed to one's boat speed (what it would be in neutral waters) to get a sometimes much faster speed.
Given :
Displacement , y = 0.75 m .
Angular acceleration ,
.
Initial angular velocity ,
.
To Find :
The value of vertical velocity after time t = 0.25 s .
Solution :
By equation of circular motion is given by :

Putting all given values we get :

Now , vertical velocity is given by :

Therefore , the numerical value of the vertical velocity of the car at time t=0.25 s is 4.90 m/s .
Hence , this is the required solution .
Remember your kinematic equations for constant acceleration. One of the equations is

, where

= final position,

= initial position,

= initial velocity, t = time, and a = acceleration.
Your initial position is where you initially were before you braked. That means

= 100m. You final position is where you ended up after t seconds passed, so

= 350m. The time it took you to go from 100m to 350m was t = 8.3s. You initial velocity at the initial position before you braked was

= 60.0 m/s. Knowing these values, plug them into the equation and solve for a, your acceleration:
Your acceleration is approximately
.
In a circular motion scenario, the force that pulls the revolving object towards the centre is the force that produces the centripetal acceleration. So, in this case, the tension on the string is the force that pulls the puck towards the centre.
Therefore, it is the tension in the string that causes the centripetal acceleration of the puck
Hope I helped!! xx
1000 kcal because you only get 10% of the energy of the thing you eat