Answer:
Final velocity= 84 m/s
Explanation:
V final= V initial + a * t
Vf = 0+ 12 (7)
Vf= 84 m/s
Answer:
Q1: c
Q2: a
Explanation:
you can tell the factors by looking at the formulas for kinetic and potential energy
for question 1 look at the formula for kinetic energy
the variables needed in order to calculate an object's kinetic energy are mass and velocity.
hence, when mass and velocity changes, kinetic energy changes, showing that mass and velocity are the factors affecting kinetic energy
same thing for the second question
as g (acceleration due to gravity) is considered constant (10 
) it will not be considered as a factor
and thus, the factors affecting potential energy are mass and height
In Burglar alarm, LDR acts an AND gate.
Answer: C
Explanation
The LDR is light dependent resistor. The principle used in the working of LDR is that the resistance is inversely proportional to the intensity of light falling on the diode.
In burglar alarm, LDR diode is combined with an IC 555.
Normally an LED source is made to be incident on the LDR diode with same intensity such that the resistance will be maintained constant.
As the LDR is connected with IC, the voltage will be high when light is falling on the diode.
The IC will give only two output states that is high and low. This confirms that LDR in burglar alarm act as AND gate.
As the thief enters and crosses the LED light, the intensity of the light falling on the diode will decrease leading to decrease in the voltage which will cause the alarm to beep.
Humans,trees,plants hope it helps
