<h3><u>Answer</u>;</h3>
<u>D. 11.8 m/s</u>
<h3><u>Explanation;</u></h3>
Using the equation;
v = u + at; such that v is the velocity attained, u is the initial velocity and a is the acceleration;
In our case, acorn falling from a tree is described as free fall aided by gravity;
Therefore, initial velocity is zero, u = 0, and the acceleration is due to gravity, thus, a = 9.8 m/s² , t = 1.2 seconds
Thus;
The equation becomes;
v = gt , since; u =0, and a = g = 9.8 m/s²
v = 9.8 × 1.2
= 11.76 m/s
<u> ≈ 11.8 m/s</u>
d = distance = 0.76 m <span>
<span>a = acceleration due to gravity = 9.81 m/s^2</span>
u = initial velocity = 0 (as the ball rolls off the table the
vertical velocity = 0
t = time = missing so we need to solve it
So we use the equation d = ut + 1/2 at², and ever since u is
zero, ut is zero and the equation becomes to d = 1/2 at² and this reorders to t
= sqrt (2d/a) = 0.39 seconds.
Since there are no forces performing in the horizontal
direction, this means that there is no acceleration in the horizontal direction
and consequently the horizontal velocity is persistent. </span>
Velocity = distance/
time.
Horizontal velocity is
therefore horizontal distance/time = 0.61 m/0.39s = 1.56 m/s.
<span> </span>
Note:
1 A (armstrong) = 10⁻¹⁰ m
1 nm (nanometer) = 10⁻⁹ m
Given:
Radius of a krypton atom = 1.9 A = 1.9 x 10⁻¹⁰ m
Part (a)
Answer: 0.019 nm
Part (b)
The diameter of a krypton atom = 2*1.9A = 3.8 A = 3.8 x 10⁻¹⁰ m.
The number of krypton atoms within a length of 1.0 mm is
Answer: About 2.632 x 10⁶ atoms
Part (c)
The radius of a krypton atom is
1.9 A = (1.9 x 10⁻¹⁰ m)*(10² cm/m) = 1.9 x 10⁻⁸ cm
The volume of a krypton atm is
Answer: 2.873 x 10⁻²³ cm³
Answer:
conduction
Explanation:
Conduction transfers heat via direct molecular collision. An area of greater kinetic energy will transfer thermal energy to an area with lower kinetic energy. Higher-speed particles will collide with slower speed particles.
It depends what the experiment is, but field experiments are more realistic and therefore more applicable to real life