Physics Answers

A 60g bullect is fired at a target that presents an average resistive force to the passage of the bullet of 20KN per metre thickness of the material from which it is constructed. If the bullet strikes the target at 600m/s, what does the minimum thickness of target have to be to stop the passage of bullet completely.

Pushing over the file cabinet to keep out the

zombies requires 1000 N of force. The cabinet

accelerates at 20 m/s

2

. What is the mass of the

cabinet?

Consider a sphere of radius R. It is a three-dimensional shape that is bounded by its surface area, a two-dimensional shape. The mathematical equation for the sphere is:

R2 = x² + y² + z². Write the expression for volume (enclosed quantity) and the surface (bounding quantity) of this sphere.

Four electrons are situated at the corners of a rectangle (l=4m; w=2m). Find the resultant force electron A will experience dur to the charges at the other corners of the triangle. The green circle below represents electron A.

Find the electric flux through the left and right sides of an equilateral triangular prism of side 2.00 m when placed in a horizontal unform electric field of 5.0 N/C directed to the right.

1.What typecof materials were able to conduct electricity?

2.what type of materials were NOT able to conduct electricity?

3.when electricity moves easily through an object,we call it a?

4.when electricity does not move easily through an object,we call it a?

Explain the following processes of charging.

1.Charging by friction

2.charging by conduction

3.charging by induction

Show that the equation 𝑣=√t/μ

does give the

appropriate units for velocity.

A car moving along straight road at 30m/s slows uniformly to a speed of 10m/s in a time of 5.0s. Determine

(a) acceleration of the car

(b) distance it moves during the third second

A stone is thrown straight upwards and it rises to a maximum height of 20m. With what speed was it thrown?