Correct matching:
1 acceleration -->
rate of change in velocity, which is the change in velocity divided by the change in time
2. speed --> the rate at which an object changes position when traveling in a certain direction
4. gravity --> force of attraction between all masses in the universe
5. Inertia --> an object´s resistance to a change in motion
3. friction --> force of resistance acting between objects in contact and tending to dampen their motion
6. velocity --> the rate at which an object changes position
Answer:
10 km East
Displacement is the shortest path between two points.
When light travels from a medium with higher refractive index into a medium with lower refractive index, there is a maximum angle (called critical angle) for which all the light is reflected, so there is no refraction.
The value of the critical angle is given by:

when n1 is the refractive index of the first medium, while n2 is the refractive index of the second medium. In our case, n1=1.33 (the water) and n1=1.00 (the air). Putting numbers in, we get
Answer:
Explanation:
Given
Minute hand length =16 cm
Time at a quarter after the hour to half past i.e. 1 hr 45 min
Angle covered by minute hand in 1 hr is 360 and in 45 minutes 270


(c)For the next half hour
Effectively it has covered 2 revolution and a quarter

angle turned 
(f)Hour after that
After an hour it again comes back to its original position thus displacement is same =25.136
Angle turned will also be same i.e. 