When light crosses the boundary between layers with different densities, the light is refracted. (A).
The period of a pendulum is given by

since Karachi is near sea level, g is larger than it is on Mt. Everest. That means the pendulum will have a larger period on Mt. Everest than it would in Karachi.
Answer:
I think it’s 6.8 m/s2
Explanation:
Please give me brainlist if the answer is right.
Suppose car A is moving with a velocity Va, and car b with a velocity Vb,
According the principle of conservation of momentum:
Va x Ma + Vb x Mb = (Ma + Mb) V
V = (Va x Ma + Vb x Mb)/(Ma +Mb)
V = speed of cars after coupling
V = (Va x 20 mg + Vb x 15 mg)/(20 mg + 15 mg)
Put in the values of Va and Vb, and get the V