Answer:
Janna levin is a cosmologist and professor at physics.
She is an american by race
She was the presenter of Nova feature Black hole Apocalypse and has writtenany science non-fiction books
www.jannalevin.com is her own page where u get her correct info and bio
Answer:
The car slowing from 60 m/s to 0 m/s
Explanation:
The bird flying at 10m/s for 10 seconds will have the same speed for those 10 seconds. So we can say it doesn't have a varying speed (During those 10 seconds, we don't have any information about what happens later).
The fish moving at 2m/s for 5 minutes will have the same speed for those 5 minutes. So we can say it doesn't have a varying speed (During those 5 minutes, we don't have any information about what happens later).
The car traveling the speed limit, we know that his speed is the speed limit. It doesn't change.
The car slowing from 60 m/s to 0 m/s needs to change his speed in order to go from 60 m/s to 0 m/s. The speed will decrease progressively until the car completely stops.
Answer:
Explanation:
It is given that,
Speed of P- waves, v = 9 km/s = 9000 m/s
The density of rock is about 
We need to find the average bulk modulus of Earth's crust. Let it is given by B. So,
So, the bulk modulus of the Earth's crust is 
.
Answer:
Is the mass number
Explanation:
Every atom is usually identified by using two different numbers:
- Atomic number: generally labelled with Z, corresponds to the number of protons in the nucleus, so Z = p
- Mass number: generally labelled with A, corresponds to the number of protons+neutrons in the nucleus, so A = p + n
To find the number of neutrons in a nucleus, therefore, we can do
n = A - Z
Answer:
0.130
Explanation:
From the given data, the coefficient of static friction for each trial are:
1. 0.053
2. 0.081
3. 0.118
4. 0.149
5. 0.180
6. 0.198
The sum of the coefficient of static friction = 0.053 + 0.081 + 0.118 + 0.149 + 0.180 + 0.198
= 0.779
So that;
the average coefficient of static friction = 
= 
= 0.12983
The average coefficient of static friction is 0.130
