Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that the friction force on two boxes is given as



Now we know by Newton's II law

so we have




Part b)
For block B we know that net force on it will push it forward with same acceleration so we have




Part c)
If Alex push from other side then also the acceleration will be same
So for box B we can say that Net force is given as




Answer:
Distance / Time = Speed
Explanation:
This is because you want to see how much distance you cover within a time interval.
For example, MPH, is a unit for speed, which is miles (distance) per hour (time)
Answer:
The mass of coal is 108 kg.
Explanation:
Given that,
Energy of coal = 1200 kg
Mass of aluminum = 1.0 kg
Energy required for single soda can = 15 g of Al
Energy required for 6 pack of cans = 
We need to calculate the mass of coal
Using formula of mass

Put the value into the formula

Put the value into the formula

Hence, The mass of coal is 108 kg.
Answer: Sound waves will not be transformed into electrical signals.
Explanation: Just took the test and got a 100!
Our sun is quite average when looking at all the stars in the Universe. There are stars that are smaller, like Wolf359, and there are also larger stars, like Betelgeuse. Our sun is essentially right in the middle of the star-size spectrum.