Answer:
3d shape is the shape of solid
-1- was created in the 1600 by william gilbert
-2-When the charge is positive, electrons in the metal of the electroscope are attracted to the charge and move upward out of the leaves. This results in the leaves to have a temporary positive charge and because like charges repel, the leaves separate. When the charge is removed, the electrons return to their original positions and the leaves relax
3-
An electroscope is made up of a metal detector knob on top which is connected to a pair of metal leaves hanging from the bottom of the connecting rod. When no charge is present the metals leaves hang loosely downward. But, when an object with a charge is brought near an electroscope, one of the two things can happen.
Answer:
The final velocity of the ball is 39.2 m/s.
Explanation:
Given that,
A ball is dropped from rest from a high window of a tall building.
Time = 4 sec
We need to calculate the final velocity of the ball
Using equation if motion

Where, v = final velocity
u = initial velocity
g = acceleration due to gravity
t = time
Put the value into the formula


Hence, The final velocity of the ball is 39.2 m/s.
Answer:
Explanation:
Height covered = 12m
time to fall by 12 m
s = 1/2 gt²
12 = 1/2 g t²
t = 1.565 s
Horizontal distance of throw
= 8.5 x 1.565
= 13.3 m
This distance is to be covered by dog during the time ball falls ie 1.565 s
Speed of dog required = 13.3 / 1.565
= 8.5 m /s
b ) dog will catch the ball at a distance of 13.3 m .