## Saturday, December 19, 2015

### 2. A thin spherical shell of radius x₁ cm has x₂ µC of charge uniformly distributed over its surface. What is the electric flux through an area of x₃ m² of a spherical surface concentric with the shell of charge but having a radius of x₄ m?

x₁, x₂, x₃, and x₄ are some numbers.
Answer: 8.99∙10⁴∙ x₂ ∙ x₃ / x₄² N∙m²/C

## Sunday, December 6, 2015

### SI Prefixes

A photo posted by Vasiliy S. Znamenskiy (@znamenski) on

## Monday, May 25, 2015

### What is the escape velocity of a rocket?

What is the escape velocity of a rocket launched from position A, the center of the three planet system depicted in the figure. Each planet has mass M, radius R, and the distance between the center of any planet and position A is r.

## Thursday, May 7, 2015

### A ball is thrown…

1. A ball is thrown downward from a 40 m high building with a speed of 10 m/s. What is the vertical component of the velocity when it hits the ground? (Use gravity g = 10 m/s²)

2. A ball is thrown downward from a 40 m high building with a speed of 10 m/s. What is the horizontal component of the velocity when it hits the ground? (Use gravity g = 10 m/s²)

3. A ball is thrown downward from a 40 m high building with a speed of 10 m/s. What is the speed of the ball when it hits the ground? (Use gravity g = 10 m/s²)

4. A ball is thrown upward from a 40 m high building with a speed of 10 m/s. What is the vertical component of the velocity when it hits the ground? (Use gravity g = 10 m/s²)

5. A ball is thrown upward from a 40 m high building with a speed of 10 m/s. What is the horizontal component of the velocity when it hits the ground? (Use gravity g = 10 m/s²)

6. A ball is thrown upward from a 40 m high building with a speed of 10 m/s. What is the speed of the ball when it hits the ground? (Use gravity g = 10 m/s²)

7. A ball is thrown horizontally from a 45 m high building with a speed of 10 m/s. What is the horizontal component of the velocity when it hits the ground? (Use gravity g = 10 m/s²)

8. A ball is thrown horizontally from a 45 m high building with a speed of 10 m/s. What is the vertical component of the velocity when it hits the ground? (Use gravity g = 10 m/s²)

9. A ball is thrown horizontally from a 45 m high building with a speed of 40 m/s. What is the speed of the ball when it hits the ground? (Use gravity g = 10 m/s²)

10. A ball is thrown horizontally from a 45 m high building with a speed of 10 m/s. This building located on an aliens' planet with the gravity acceleration of 20 m/s². What is the horizontal component of the ball velocity when the ball hits the ground?

11. A ball is thrown downward from a window of a 40 m high building with a speed of 10 m/s. What is the speed of the ball when it hits the ground? (Use gravity g = 10 m/s²)

12. A ball is thrown from the roof of a 40 m high building with a speed of 10 m/s. What is the speed of the ball when it hits the ground? (Use gravity g = 10 m/s²)

13. A ball is thrown from the roof of a X1 m high building with a speed of X2 m/s at an angle of X3 degree with respect to the horizontal. What is the velocity of the ball when it hits the ground? (Use gravity g = 10 m/s²)

## Saturday, April 25, 2015

### An object is being pushed up an inclined plane with a constant force F

 An object is being pushed up an inclined plane with a constant force F. The plane makes an angle θ with respect to the horizontal. The object is moving with constant velocity. The coefficient of kinetic friction between the object and the surface is µk. What is the mass of the object? From Calculus-Based Physics I: Problems with Solutions

### An object is launched up Ns degree slope at an angle of Na degrees above the incline of the slope

 An object is launched up Ns degree slope at an angle of Na degrees above the incline of the slope with an initial speed of S0 m/s. How far up the slope does the object land? From Calculus-Based Physics I: Problems with Solutions

### A ball of mass M is thrown from the ground at an angle of α from the vertical with a speed S

A ball of mass M is thrown from the ground at an angle of α from the vertical with a speed S. The ball lands on top of a building that height is h. What is the speed of the ball just before it lands on the roof of the building?
 From Calculus-Based Physics I: Problems with Solutions

### A car moving along the x direction has acceleration, ax that varies with time

A car moving along the x direction has acceleration, ax that varies with time as shown in the figure. At the moment, t = 0 s, the car is located at x0 = 1.0 m and has a velocity v0 of 2.0 m/s in the positive x direction. What is the position of the car at t = 3.0 s?

## Thursday, April 16, 2015

### What is Magnitude of Angle between Vectors?

The vector A = (Ax , Ay) = ( +2.0 m, +2.0 m) and the vector B = (Bx , By) = ( +1.0 m, -1.0 m).
What is the magnitude of the angle between the vectors A and B?