X- rays. It can damage living tissue
Answer:
Bouyancy
Explanation:
Bouyancy occurs when the upthrust exerted on an object is equal to the weight of object displaced. It is mostly applicable to low density objects for example balloon. When balloon is displaced in water, it floats. This is due to the effect of the upthrust acting on the balloon which allows the balloon to float and which is opposite the weight.
Note that the weight acts downwards the object while the upthrust always acts opposite (upward)
Answer:
a)
b)
c)
d)
e)
Explanation:
Given that:
- initial speed of turntable,

- full speed of rotation,

- time taken to reach full speed from rest,

- final speed after the change,

- no. of revolutions made to reach the new final speed,

(a)
∵ 1 rev = 2π radians
∴ angular speed ω:

where N = angular speed in rpm.
putting the respective values from case 1 we've


(c)
using the equation of motion:

here α is the angular acceleration



(b)
using the equation of motion:





(d)
using equation of motion:



(e)
using the equation of motion:



Answer:
t = 13.7 s or t = 14 s with proper significant figures
Explanation:
The initial speed is 0 m/s since the car starts from rest, acceleration is 5.5 m/s2 and distance is 523 m.
Since we have initial speed, acceleration and distance we can use the following formula to find the time. We can now use algebra to work out our answer.
d = vt +
at²
523 = (0)t + (
)(5.5)t²
523 = 2.8t²
186.8 = t²
13.7 s = t
(t = 14 s with proper significant figures)