Final velocity(v) = 32 m/s
Initial velocity(u) = 10 m/s
Using kinematic equation v = u + at,
32 = 10 + a(3)
32-10
--------- = a
3
a = 22
----
3
a = 7.3 m/s^2.
Hence acceleration of the roller coaster is 7.3 m/s^2.
Hope this helps!!
C
a mountain range will form
Answer: Boyle's law
Explanation: It states that pressure of a gas is inversely proportional to the volume of a gas at constant temperature.
∝
at constant temperature
or If the pressure of gas is decreased, the volume increases if the temperature is unchanged and If the pressure of gas is increased, the volume decreases if the temperature is unchanged.

Answer: a)
: negative
b)
: positive
c)
: positive.
d)
: negative
e)
: positive.
f)
: positive.
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
is positive when randomness increases and
is negative when randomness decreases.
a) 
As ions are moving to solid form , randomness decreases and thus sign of
is negative.
b) 
As solid is changing to gas, randomness increases and thus sign of
is positive.
c) 
As 2 moles of reactants are converted to 4 moles of products , randomness increases and thus sign of
is positive.
d) 
As gas is changing to solid, randomness decreases and thus sign of
is negative.
e) 
As 7 moles of reactants are converted to 8 moles of products , randomness increases and thus sign of
is positive.
f)
As solid is changing to gas, randomness increases and thus sign of
is positive.