Answer:
A plain mirrior is a mirrior with flat reflective surface.
hope it is helpful for you.
If we pull an object vertically upwards then we need to apply a force which is equal in the magnitude of the weight of the object

now when we pull the same object upwards along an inclined plane with angle then we require a force which will balance the component of weight along the inclined
so it is given as

so as if we compare the two forces we can say that since the value of sine is always less than 1 for an angle less than 90 degree
so in the 2nd case when we pull the object along the inclined plane it will require less effort
so correct answer is
<em>A. reduce effort</em>
Answer:
The entropy of a gas increases when it expands into a vacuum because the number of possible states increases .
Explanation:
When a gas expand in a vacuum, the molecules of the gases vibrates very fast and starting moving with higher velocity in random directions which means the level of disorder in the gases increases.
Now the possible state of the gas molecule increases such as the particle can be located at different position due to increased randomness.
<u>Entropy is the measure of this randomness and thus with this increased randomness entropy also increases.</u>
Answer:
a) 0.05s
b) 4000N
Explanation:
a)When car is stopped its final velocity become zero
U- 10 m/s
V- 0 m/s
S - 0.25 m
t -?
S = (v+u)*t/2
0.25 =(10+0)*t/2
t = 0.05s
b) If we happened to calculate the avarage force we have to consider about acceleration
V= 0
U = 10
t = 0.05 s
a =?
V = U + at
0 = 10 -a * 0.05
a = 200 m/s2
F = m *a
= 20 * 200
= 4000N
It's cold outside, the water vaper in your breath condenses into tiny droplets of liquid water and ice that you can see.