Answer:
15.7 m/s
Explanation:
The motion of the cannonball is a accelerated motion with constant acceleration g = 9.8 m/s^2 towards the ground (gravitational acceleration). Therefore, the velocity of the ball at time t is given by:
where
u = 0 is the initial velocity
g = 9.8 m/s^2 is the acceleration
t is the time
If we substitute t=1.6 s into the equation, we find the final velocity of the cannonball:
Answer:
Option (b)
Explanation:
Let the ball takes time t to reach the maximum height. The final velocity at maximum height is zero.
Use I equation of motion, we get
V = u + gt
0 = 3 - 9.8 x t
t = 0.306 s
As the air friction is negligible, so the ball takes same time to reach the hand of boy. Thus the time taken by the ball in air is
T = 2 t = 2 x 0.306 = 0.61 s
High melting and boiling point
ionic bonds are very strong
a lot of energy is needed to break them
conductive when liquid
ionic com. can only conduct electricity if their ions are free to move
Answer:
-1.11 m/s²
Explanation:
v = at + v₀
Given v = 20 m/s, v₀ = 120 m/s, and t = 1.5 min = 90 s:
20 m/s = a (90 s) + 120 m/s
a = -1.11 m/s²