Physics Answers

A spring is hung from the ceiling. When a 0.450-kg block is attached to the free end of the spring and released from rest, the block drops 5.0 cm before momentarily coming to rest, after which it moves back upward. What is the spring constant of the spring?

An object is being shot from a horizontal ground at an incline angle of 30 degree with respect to the ground at a speed of 49 m/s. Find the duration in seconds that the object is above the height of 13 m. Give your answer with one decimal place.

What force is there between two charges, each with 2.0 x 10^-6 C if they are 0.03 m apart?  

a simple pendulum has a period of 2.4s on earth. the height of the bob is 0.5m. what will linear velocity of the bob be at the bottom of its swing

Two small sphere spaced 20.0 cm apart have equal charge. How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57x10^-21 N?

An arrow moving at 10 m/s is stopped by a target. If the arrow has a mass of 250 g and penetrates 4 cm into the target, what is the force exerted by the arrow on the target?

What is the third harmonic of a pitch with a base frequency of 314 Hz?

What is the radius of the nucleus of 28/14 Si ? What is its volume?

What nuclide is formed when 20/10 Ne undergoes beta-plus decay?

What nuclide is produce when 235/93 Np undergoes electron capture?

The speed of light is 299,792,458 m/s.

a. Express this number in standard form.

a. Express speed of light up to three significant figures.