I'm assuming it was to keep the data consistent? The further you are from a heat source the less heat will get to you as the temperature tries to reach equilibrium and the waves start to spread out, so you should keep everything the same distance to get consistent results. I don't have any information so this is just my assumption
So i believe is exercise:)
Force = mass × accelaration
Force = 0.25Kg × 196 m/s²
Force = 49 Newtons
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.
To solve this problem, we use the formula
λ = s sin θ
where s is the separation and θ is the angle interference
So,
λ = 20 x 10^-6 sin 2.5
λ = 8.72 x 10^-7 m
The required angle for the fourth order bright fringe is
θb = sin⁻¹ (4λ / s) = sin⁻¹ (4 (8.72 x 10^-7 m)/ 20 x 10^-6 ) = 10.04°
The required angle for the fourth order dark fringe is
θd = sin⁻¹ (4.5 λ / s) = sin⁻¹ (4.5 (8.72 x 10^-7 m)/ 20 x 10^-6 ) = 11.31°