You can deal with this question using the collision theory, which states that the chemical reactions occur when particles collide with enough energy to reach the Activation Energy.
The velocity of the particles is related with the temperature. At higher temperatures, higher velocities and higher frequency of collisions.
Also, at higher concentration (more particles is a same volume) the number of collisions will increase.
Then, hIgher concentration and higher temperature will increase the frequency of the molecular collisions..
Then, the answer is the proposal #1: "<span>increasing the frequency of molecular collisions"</span>
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.
Answer:
2.24 m/s
Explanation:
resolving force of 29.2 N in x component
Fx = 29.2 cos 57.7
Fx = 15.6N
as force of friction is 12.7 N hence net force which produces acceleration is
15.6-12.7=2.9 N
by Newton 's law a=f/m
a= 2.9/6.87=0.422 m/s^2
now equation of motion is
v^2= U^2+2as
= 0^2+2(.422)(5.93)
v^2=5.00
v=2.24 m/s
Answer:
5.6
Explanation:
F=kx is the formula for spring force. If Extension versus Force was graphed, a linear relation would appear, where the slope is the k value, aka the spring constant.
