<u>Answer:</u>
Cannonball will be in flight before it hits the ground for 2.02 seconds
<u>Explanation:</u>
Initial height from ground = 20 meter.
We have equation of motion , , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
In this the velocity of body in vertical direction = 0 m/s, acceleration = 9.8 , we need to calculate time when s = 20 meter.
Substituting
So it will take 2.02 seconds to reach ground.
Answer:
If both the radius and frequency are doubled, then the tension is increased 8 times.
Explanation:
The radial acceleration (), measured in meters per square second, experimented by the moving end of the string is determined by the following kinematic formula:
(1)
Where:
- Frequency, measured in hertz.
- Radius of rotation, measured in meters.
From Second Newton's Law, the centripetal acceleration is due to the existence of tension (), measured in newtons, through the string, then we derive the following model:
(2)
Where is the mass of the object, measured in kilograms.
By applying (1) in (2), we have the following formula:
(3)
From where we conclude that tension is directly proportional to the radius and the square of frequency. Then, if radius and frequency are doubled, then the ratio between tensions is:
(4)
If both the radius and frequency are doubled, then the tension is increased 8 times.