Which of the following is true about frictional forces?

you recover a bullet from the wall at a crime scene and you need to know what caliber of gun shot this bullet. Explain how you would determine the caliber of this bullet

Should commercial buildings be required to use alternative fuel sources to fulfill a minimum of 25% of their energy needs?

What did isaac Newton believe light was made of

A proton moving at 4.80 10⁶ m/s through a magnetic field of 1.52 T experiences a magnetic force of magnitude 7.95 10⁻¹³ N. What is the angle between the proton's velocity and the field?

X=3t^2-12t+5 calculate time t=1 and time when velocity zero

What is the explanation for feather beds being warm

A student wearing frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 47 N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 354 J?

Suppose a rocket ship in deep space moves with constant acceleration equal to 9.8 m/s2, which gives the illusion of normal gravity during the flight.

A canoeist on a lake throws a 0.145 kg baseball at 20.0 m/s to a friend in a different canoe. Each canoe with its contents has a mass of 120 kg, and is at rest initially.

You short-circuit a 9 volt battery by connecting a short wire from one end of the battery to the other end. if the current in the short circuit is measured to be 18 amperes, what is the internal resistance of the battery?