:
Distance Covered: 2 Marks
Average Speed: 2 Marks
Steps: 1 Mark
John drove the first 30 minutes at 30 km/hr and then changed his speed to 60 km/hr for the next 30 mins. Hence, total distance traveled by John will be the distance he covers in the entire 1 hour.
Time = 0.5 hr
Speed = 30 km/hr
Distance covered $=speed\times time=30\times 0.5=15km$
Now, new speed = 60 km/hr
Time = 0.5 hr
Distance covered $=speed\times time=60\times 0.5=30km$
Total distance covered by him = 15 + 30 = 45 km in one hour.
$Averagespeed=\frac{Totaldistancetravelled}{Totaltime}$
Average speed $=\left(\frac{45}{1}\right)\frac{km}{hr}$
Average speed = 45 km/hr

:
Sundial: 1 Mark
Working: 1 Mark
Sundials are the oldest known instruments for telling time. The surface of a sundial has markings for each hour of daylight. As the Sun moves across the sky, another part of the sundial casts a shadow on these markings. The position of the shadow shows what time it is.
Sundial works on the principle that the sun takes up similar positions each day. Depending on the location of the sun with respect to the dial, the dial would have different shadows by which people can approximately tell the time of the day.

:
Each option: 1 Mark each
1)Straight line
2) Oscillatory motion
3) Oscillatory motion
4) Straight line
5) Circular motion

:
Explanation: 1 Mark
Determination of speed: 1 Mark
The above statement implies that Vehicle A is covering a larger distance as compared to Vehicle B in the same time period.
To identify the faster vehicle, we can calculate the speed of both vehicles. The one with more speed will be faster.

:
Definition: 1 Mark
Working: 2 Marks
A speedometer is a device that measures the speed of a particular vehicle at that particular instant.
The speedometer calculates the speed of the vehicle at a particular instant by measuring the time it takes for the wheels of the vehicle to rotate. Since the distance moved in each rotation is constant, knowing the time it takes for one rotation gives us the speed.

Answer: Option B. -> The object is in motion with respect to A.
:
B and C

An object is said to be in motion when its position changes with respect to the reference point.
In this situation, there are two reference points, A and B. From the point of view of A, the object is changing its position. Hence, it's said to be in motion with respect to A. 
From the point of view of B, the object is not changing its position. Hence, it's said to be at rest with respect to B.

Answer: Option B. -> speed
:
B

We know that:
$Speed=\frac{Distance}{Time}$
Here, the object has to cover a certain fixed distance in a shorter span of time.
From the equation above, we understand that greater the speed, lesser is the time taken, provided the distance is constant.
So, in order to cover a certain distance in a shorter time span, the object should have a greater speed.

Answer: Option A. -> $20km{h}^{-1}$
:
A

Given:
Odometer reading, before the trip $=22256km$.
Odometer reading, after the trip $=22356km$.
So the distance travelled in the trip$=22356-22256=100km$.
Time taken for the trip $=5h$.
Average speed = $\frac{\text{Total distance travelled}}{\text{Total time taken}}$
$\therefore$Average speed $=\frac{100}{5}=20km{h}^{-1}$.

Answer: Option A. -> $50km$
:
A

Given, 
Speed $=5kmph$ and Time $=10h$
We know that:
Distance $=$ Speed $\times$ Time
$\Rightarrow$Distance $=5\times 10=50km$.

Answer: Option C. -> straight line having ${45}^0$ to X-axis
:
C

In uniform motion, a body covers an equal distance in equal interval of time.
Hence, the ratio $\frac{\text{Change in distance}}{\text{Change in time}}$ is constant. When we plot the graph with distance on the Y-axis and time on the X-axis, we see that the points lie along a straight line inclined at ${45}^0$ with the x-axis.