It depends on how many hours!
1 hour = 40km
2 hours = 80km
D is the correct answer, assuming that this is the special case of classical kinematics at constant acceleration. You can use the equation V = Vo + at, where Vo is the initial velocity, V is the final velocity, and t is the time elapsed. In D, all three of these values are given, so you simply solve for a, the acceleration.
A and C are clearly incorrect, as mass and force (in terms of projectile motion) have no effect on an object's motion. B is incorrect because it is not useful to know the position or distance traveled, unless it will help you find displacement. Even then, you would not have enough information to use a kinematics equation to find a.
Answer:
Explanation:
separation between two gaps, d = 5 cm
angle between central and second order maxima, θ = 0.52°
use
d Sinθ = n λ
n = 2
0.05 x Sin 0.52° = 2 x λ
λ = 2.27 x 10^-4 m
λ = 226.9 micro metre
Friction produces heat hope this helps
