Answer:
Potential gradient = 1.6 v/m
E.M.F. = potential gradient × balancing length 1.2 = 1.6 × l
l=1.2\1.6
=3\4
3\4=0.75m
convert m into cm 0.75x10
0.75m=75 cm
ans=75 cm
Explanation:
They're never the same ray.
Answer:
1. Two substances burst into flames on contact
Explanation:
For a chemical reaction to occur between two or more substances, the reaction process must be reversible in nature.
According to options 2,3 and 4, they are all reversible reactions that is the product formed can return back to their original form except for the first option which is an irreversible reaction. Hence, two substances burst into flames on contact is not an indication of a chemical reaction since the burnt substances cannot return back to their original form. For example burning of paper into ashes is not a chemical change because ashes which is the final product cannot turn back to its original form which is paper.
<u>Answer:</u>
The stopping car has negative acceleration.
<u>Explanation:</u>
We know acceleration is the rate of change of velocity. That is
Acceleration(a) = ( Final velocity - Initial velocity )/ Time taken.
Here Final velocity = 0 km/h( car stops) and initial velocity = 30 km/h
So acceleration = (0-30)/time = -30/ time
Time is always positive , so -30/time is negative, so the stopping car has negative acceleration.
Answer:
m₂ = 15660 kg
Explanation:
Given that,
Before collision,
Mass of box car 1, m₁ = 8700 kg
Speed of box car 1, u₁ = 14 m/s
Speed of box car 2, u₂ = 0 (at rest)
After collision,
The two stick together and move off with a speed of 5 m/s
Let m₂ is the mass of the second car. As cars stick together, it is a case of inelastic collision. Using the conservation of momentum as follows :
So, the mass of the second car is 15660 kg.