Question

1.
A particle travels half the distance of a straight journey
with a speed 5 m/s. The remaining part of the distance
is covered with speed 6 m/s for half the remaining
time, and with speed 4 m/s for the other half of the
remaining time. The average speed of the particle is
(1) 3 m/s
(2) 4 m/s
(3) m/s
(4) 5 m/s​

Answer 1

Answer:

$average \: speed \: = \frac{total \: distance \: covered}{total \: time \: taken}$

$= \frac{5m + 6m + 4m}{3s}$

$= \frac{15 }{3}$

=5m/s

☄Hope it helps☄

Answer 2

Chemical weathering typically increases as temperatures rise and rain falls, which means rocks in hot and wet climates experience faster rates of chemical weathering than do rocks in cold, dry climates.

Physical weathering occurs more often in cold climates, because the different minerals within rocks expand and contract at different rates when they are heated and cooled. Repeated heating and cooling cycles eventually cause rocks to fracture. Desert and mountain climates experience a wide range of temperatures from low to high during a day and night, which accounts for the breakdown of rocks known as physical weathering.

Biological weathering occurs when living organisms break up rocks. Tree roots, for example, can fracture rocks in the same way they buckle pavement. Warm, humid climates are most favorable to life. Contrast the rich diversity of life in a rainforest, for example, with the scarcity of life in the dry Sahara or the frigid Antarctic. Consequently, rates of biological weathering are most rapid in warm humid climates like those in tropical regions.