Mass/volume is the formulae
92 grams of Y would combine with 46 grams of X
We have to choose the correct name for the zone along the southern margins of the Sahara. Laterite is a soil in hot and wet tropical areas. Savanna is the tropical grassland. It has tropical savanna climate. Veldt is name for the areas in the South Africa. Finally, the Sahel is the zone along the south margins of the Sahara. It has a semi-arid climate. The Arabic word "sahel" means "coast". Answer: C. Sahel. <span> </span>
Explanation:
Mass of the ball, m = 0.058 kg
Initial speed of the ball, u = 11 m/s
Final speed of the ball, v = -11 m/s (negative as it rebounds)
Time, t = 2.1 s
(a) Let F is the average force exerted on the wall. It is given by :


F = 0.607 N
(b) Area of wall, 
Let P is the average pressure on that area. It is given by :


P = 0.202 Pa
Hence, this is the required solution.
The layout of the stars in the sky is determined by the date, time of night, and your location (mainly latitude). So to pick the best star chart, you should go with the one that's closest to the present date and your location, then make allowance for what time it is. Everything in the sky moves about a degree every 4 minutes.