Answer:
The velocity of the ball before it hits the ground is 381.2 m/s
Explanation:
Given;
time taken to reach the ground, t = 38.9 s
The height of fall is given by;
h = ¹/₂gt²
h = ¹/₂(9.8)(38.9)²
h = 7414.73 m
The velocity of the ball before it hits the ground is given as;
v² = u² + 2gh
where;
u is the initial velocity of the on the root = 0
v is the final velocity of the ball before it hits the ground
v² = 2gh
v = √2gh
v = √(2 x 9.8 x 7414.73 )
v = 381.2 m/s
Therefore, the velocity of the ball before it hits the ground is 381.2 m/s
Given: Mass m = 44 Kg; Velocity v = 10 m/s
Required: Kinetic energy K.E = ?
Formula: K.E = 1/2 mv²
K.E 1/2 (44 Kg)(10 m/s)²
K.E = 2,200 Kg.m²/s²
K.E = 2,200 J Answer is A
Answer:
1.0s
Explanation:
distance = 1/2 × acceleration × time2 + intial speed × time
A) 1.55
The speed of light in a medium is given by:
where
is the speed of light in a vacuum
n is the refractive index of the material
In this problem, the speed of light in quartz is
So we can re-arrange the previous formula to find n, the index of refraction of quartz:
B) 550.3 nm
The relationship between the wavelength of the light in air and in quartz is
where
is the wavelenght in quartz
is the wavelength in air
n is the refractive index
For the light in this problem, we have
Therefore, we can re-arrange the equation to find , the wavelength in air:
