The distance an object falls, from rest, in gravity is
D = (1/2) (G) (T²)
'T' is the number seconds it falls.
In this problem,
0.92 meter = (1/2) (9.8) (T²)
Divide each side by 4.9 : 0.92 / 4.9 = T²
Take the square root
of each side: √(0.92/4.9) = T
0.433 sec = T
The horizontal speed doesn't make a bit of difference in
how long it takes to reach the floor. BUT ... if you want to
know how far from the table the pencil lands, you can find
that with the horizontal speed.
The pencil is in the air for 0.433 second.
In that time, it travels
(0.433s) x (1.4 m/s) = 0.606 meter
from the edge of the table.
Answer:
6
Explanation:
m = Mass
c = Specific heat
= Change in temperature
s denotes stone
Heat is given by

Heat for the stone

Number of stones is given by

The number of stones is 6
Answer:
The system is still balanced
Explanation:
If we suppose that the boy weights M and the girl m, and are balanced at distances L1 and L2 from the pivot point respectively, thy will be balanced if the resultant torque of all the farces from the pivot pint is cero:
(1)
now they moved to distances (L1)/2 and (L2)/2, the resultant torque will be:
(2)
1/2 can be taken out as a common factor:
(3)
As the the inside of the parenthesis equals equation (1) that equals zero, hte whole equiation equals zero:
(3)
So the system is still balanced
Answer: speed of light in solid = 1.88 * 10^8 m/s
Frequency is constant
Explanation: The relationship between the velocity of light wave and wavelength is given by the formulae below
V = fλ
During refraction, the frequency of light is constant, thus we have that
V = kλ which implies that velocity is proportional to wavelength.
Hence, we have that
v1/ λ1 = v2/ λ2
Where v1 = velocity of light in air = 3 * 10^8 m/s
v2 = velocity of sound in solid
λ1 = wavelength of light in air = 670nm
λ2 = wavelength of light in solid = 420nm
By making v2 subject of formulae, we have that
v2 = v1 * λ2/ λ1
v2 = 3 * 10^8 * 420nm/ 670nm
v2 = 3 * 10^8 * 0.6268
v2 = 1.88 * 10 ^8 m/s
b)
During refraction the frequency of light wave is constant this is because light consist of photons which has energy. it energy needs to be constant and for energy (E=hf) to be constant, frequency would be constant too.
Answer:
E. downward and constant
Explanation:
Freefall is a special case of motion with constant acceleration because the acceleration due to gravity is always constant and downward. This is true even when an object is thrown upward or has zero velocity.
For example, when a ball is thrown up in the air, the ball's velocity is initially upward. Since gravity pulls the object toward the earth with a constant acceleration ggg, the magnitude of velocity decreases as the ball approaches maximum height. At the highest point in its trajectory, the ball has zero velocity, and the magnitude of velocity increases again as the ball falls back toward the earth.