Answer:
c. 0.71 [s]
Explanation:
To solve this problem we must use the following equation of kinematics.
where:
Vf = final velocity = 0 (because when the ball reaches the top, there is no movement)
Vo = initial velocity = 7 [m/s]
g = gravity acceleration = 9.81 [m/s²]
t = time [s]
Note: The negative sign of the equation means that the movement is againts the direction of the gravity acceleration.
![0 = 7 - (9.81*t)\\t = 0.713 [s]](https://tex.z-dn.net/?f=0%20%3D%207%20-%20%289.81%2At%29%5C%5Ct%20%3D%200.713%20%5Bs%5D)
Answer:
b. 450 nm
Explanation:
The wavelength of light can be calculated by using the formula derived in Young's double slit experiment. The formula is as follows:
Δx = λL/d
Δx/2 = λL/2d
where,
Δx/2 = half distance between consecutive dark fringes = width of central maximum = 0.75 cm = 0.0075 m
λ = wavelength of light = ?
L = Distance of Screen = 1.25 m
d = width of slit = 0.15 mm = 0.00015 m
Therefore,
0.0075 m = λ(1.25 m)/(0.00015 m)
λ = (0.0075 m)(0.00015 m)/2(1.25 m)
λ = 4.5 x 10⁻⁷ m = 450 nm
Thus, the correct option is:
<u>b. 450 nm</u>
The system in the problem can be assimilated to a simple lever. The mechanical advantage (MA) of a lever is
where
is the distance of application of the input force with respect to the fulcrum, and
the distance of the output force from the fulcrum.
In our problem, MA=5.5 and
. So we can find the input distance:
Vivid writing includes tangible descriptions of
things that can be seen, touched, heard, smelled, and tasted.
Potassium belongs to group IA of the elements. This means that it will give up one of its electrons to form the cation K+. Opposite to that is bromine in which it accepts one electrons to form the anion Br-. The binding of these elements will form KBr and is formed from transfer of electron from one element to the other. This is the mechanism of ionic bond formation.
