Answer:
To unlock a door and indicate to the person that the door is now unlocked
Explanation:
Schools all have doors locked. Visitors/parents need to press a button. That creates a buzz sound in the office, secretary presses a button to unlock the door. The person trying to enter the school hears a buzz and the secretary telling them to enter the building.
Answer:
The universe began, scientists believe, with every speck of its energy jammed into a very tiny point. This extremely dense point exploded with unimaginable force, creating matter and propelling it outward to make the billions of galaxies of our vast universe. Astrophysicists dubbed this titanic explosion the Big Bang.
A :-) F = mv^2 by r
Given - m = 500 kg
v = 80.0 m/s
r = 450 m
Solution -
F = mv^2 by r
F = 500 x (80)^2 by 450
F = 500 x 6400 by 450
( cut 500 and 450 because 5 x 100 = 5 , 5 x 90 = 450 and also 90 and 6400 because 90 x 70 = 6400 )
F = 100 x 70
F = 7000
.:. The centripetal force is 7000 N
Answer:
Explanation:
Given
Radius of bicycle wheel 
Initial angular velocity 
It rotates 3 revolution in 5 s therefore
using 
where 
Total acceleration of any point will be a vector sum of tangential acceleration and centripetal acceleration
Tangential acceleration 
