Answer:
The time is 1.8s
Explanation:
The ball droped, will freely fall under gravity.
Hence we use free fall formula to calculate the time by the ball to hit the ground

Where h is the height from which the ball is droped, g is the acceleration due to gravity that acted on the ball, and t is the time taken by the ball to hit the ground.
From the question,
h=16m
Also, let take

By substitution we obtain,


Diving through by 9.8


square root both sides, we obtain


Sound waves....................................
Answer:
yes
Explanation:
because it will help find who did the crime and it can also open jobs and opportunities for the people who likes sicnenae
The energy carried by the incident light is

where h is the Planck constant and f is the frequency of the light. The threshold frequency is the frequency that corresponds to the minimum energy needed to eject the electrons from the metal, so if we substitute the threshold frequency in the formula, we get the minimum energy the light must have to eject the electrons:
Answer:
43.68 J
Explanation:
Distance moved= 7.8 m
Force = 5.6 N
Work Done= Distance moved * Force
= 7.8 *5.6
=43.68 Joules