Answer:
Because it has more mass
Explanation:
To understand this, think about the equation of kinetic energy
KE =
m 
Kinetic energy depends on both the velocity (v) as well as the mass (m).
Because a lorry is bigger and heavier than a car, it will have more mass. With more mass, at the same velocity the lorry with have more kinetic energy.
Answer:
The Doppler shift may be helpful to determine the relative speed of an object by bouncing a wave (usually a radar wave) off the object and measuring the shift in the frequency of the wave.
Explanation:
Doppler shift helps to overcome a visual illusion block out irrelevant noises, locate sounds and see an object in very dim light by determining the relative speed of an object by bouncing a wave
As long as the graph is a straight line they both will give same answer. Edit: In the case of errors,I think the most fitting slope line is more accurate method,because taking average is same as drawing a line from initial to final point of the line and taking its slope.
Hope it helps