Answer:
no change in speed, therefore the body cannot be accelerated. a=0
Explanation:
When a person is accelerating his speed must change, if the speed is in the same direction as the acceleration the speed increases and if the acceleration is in the opposite direction to the speed it decreases.
In this case there is no change in speed, therefore the body cannot be accelerated.
Answer:
B. Glass
Explanation:
An electrical insulator is a substance that does not conduct electricity.
Glass has tightly bounded electrons, that is why it is an insulator of electricity.
Answer:
Time = 0.55 s
Height = 8.3 m
Explanation:
The ball is dropped and therefore has an initial velocity of 0. Its acceleration, g, is directed downward in the same direction as its displacement, 
.
The dart is thrown up in which case acceleration, g, acts downward in an opposite direction to its displacement, 
. Both collide after travelling for a time period, t. Let the height of the dart from the ground at collision be and the distance travelled by the ball measured from the top be .
It follows that 
.
Applying the equation of motion to each body (h = v_0t + 0.5at^2),
Ball:
(since 
.)
Dart:
(the acceleration is opposite to the displacement, hence the negative sign)
But
The height of the collision is the height of the dart above the ground, .
