We use the equation of motion,
Here, S is the height, u is initial velocity and a is acceleration.
Given, 
As acorn falls from tree, therefore we take the value of 
and initial velocity 
.
Substituting these values in equation of motion,
Thus, the time taken by the acorn to fall 20 feet ( 6.096 m ) is 1.12 s.
Answer:4.05 s
Explanation:
Given
First stone is drop from cliff and second stone is thrown with a speed of 52.92 m/s after 2.7 s
Both hit the ground at the same time
Let h be the height of cliff and it reaches after time t
For second stone
---2
Equating 1 &2 we get
B. velocity at position x, velocity at position x=0, position x, and the original position
In the equation
= 
+2 a x (x - x₀)
= velocity at position "x"
= velocity at position "x = 0 "
x = final position
= initial position of the object at the start of the motion
Answer: a) 0.12m; b) 1,6 s; c) 0.625 1/s
Explanation: The simple harmonic movement can be described by a sin or cosine function in time.
This can be in the form:
X(t)= A Sin/Cos (wt+φ) where φ is initial phase o position at t=0
w the angular frequency are related to the frequency (f) as 2Pif
and f=1/T period of oscillating
Answer:
U for the reaction is 15,048.58 kJ/mol of pentane.
Explanation:
Quantity of heat required = heat capacity of bomb calorimeter × temperature rise = 5.23 kJ/C × (29.8 C - 23.7 C) = 5.23 kJ/C × 6.1 C = 31.903 kJ
Moles of pentane = mass/MW
Mass = 0.1523 g
MW of pentane (C5H12) = 72 g/mol
Moles of pentane = 0.1523/72 = 0.00212 mol
U for the reaction = quantity of heat required ÷ moles of pentane = 31.903 kJ ÷ 0.00212 mol = 15,048.58 kJ/mol
