1) velocity: 98 m/s downward
Explanation:
The marble moves by uniformly accelerated motion, with constant acceleration a=g=-9.8 m/s^2 directed towards the ground. Therefore, its velocity at time t is given by:
where
is the initial velocity
is the acceleration
is the time
Substituting t = 10 s, we find:
And the negative sign means the direction of the velocity is downward.
2) Distance covered: 490 m
The distance covered in an uniformly accelerated motion can be found with the formula:
where
is the acceleration
t is the time
Substituting t=10 s, we find
And the negative sign means the displacement is below the dropping point.
Answer:
I'm pretty sure its c
Hope you get a good grade-
So we want to know what is the age of igneous rock if it contains one half of its original amount of potassium 40. The half-life of potassium 40 is 1.251*10^9 years. Since in the igneous rock there is one half of potassium left it means only one half-life has passed. And its age is 1.251*10^9 years or 1.251 billion years.
Answer:
A
Explanation:
According to Snell's law refractive index is the ratio of the sine of the angle of incidence to the normal to the barrier ( the normal is perpendicular to the surface of the barrier) to the ratio of the sine of refraction ( the angle of emergence from the second barrier) and also equals the ratio of the speed of light in the first barrier to the ratio of the speed of light in the second barrier.
Since there is no change in the direction of the propagation of light then the two materials must have matching indexes of refraction.