49. If an atom contains 13 protons, then it has (2.4)

a. 13 electrons. b. 26 electrons. c. 13 neutrons.

d. 26 neutrons,

An electric circuit consists of a variable resistor connected to a source of constant potential difference. If the resistance of the resistor is doubled, then

Particle with a mass of 1.7 * 10-20 kg is oscillating with simple harmonic motion with a period of 3.4 * 10-5 s and a maximum speed of 2.6 * 103 m/s. calculate (a) the angular frequency and (b) the maximum displacement of the particle.

You're riding on a train that's moving at 5 km/h and you roll a ball down the aisle at 2 km/h in the same direction as the train is moving. if a person standing on the ground near the train track could see the ball how fast would it appear moving

A 6.85-m radius air balloon loaded with passengers and ballast is floating at a fixed altitude. Determine how much weight (ballast) must be dropped overboard to make the balloon rise 114 m in 17.0 s. Assume a constant value of 1.

a 1000 foot spool of bare 12-gauge copper wire weighs 19.8 pounds. How much will 18 inches of the wire weigh, in ounces?

If a car rolls gently off a vertical cliff, how long does it take to reach 90km/hr.

In the game of volleyball, what skill relates to Newton's second law

The minimum breaking distance d in feet for a typical vehicle can be modeled with the equation d (v) = 0.045v2, where v is the vehicle's speed in miles per hour.

A 2kg blob of putty moving at 4 m/s slams into a 6kg blob of putty at rest what is the speed of the to stick together blobs immediately after colliding

A stone is thrown vertically upward with a speed of 12m/s from the edge of a cliff 70 m high (a) How much later it reaches the bottom of the cliff? (b) What is its speed just before hitting? And (c) what total distance did it travel? (Ans: 5.