Which elements do hydrogen fuel cells combine to produce electricity?

How do you think the speed a satellite fall towards Earth compares to the speed it is moving forward?

A roller coaster with people on board has a total mass of 4500 kg and starts at a height of 22 meters with a speed of 2.0 m/s. 50 kJ of work is done by friction on the way to the bottom of the ride. What is the speed at the bottom of the ride?

What is quantum computing?

My reaction time was 0.7268 seconds the first time and 0.3883 the second time. What was yours

What is the cause of the Earth's magnetic field? A. The solar energy radiating from the Sun makes an impact on Earth's atmosphere and produces a magnetic field. B. The Sun exerts a gravitational pull on the planet and produces a magnetic field. C.

Two copper wires with different diameters are joined end to end. If a current flows in the wire combination, what happens to electrons when they move from the larger-diameter wire into the smaller-diameter wire?

A baseball player is warming up and tosses a ball straight up into the air. The ball travels up until it reaches some maximum height, and then falls back down to the player/'s hand.

Volume can be measured in liters or cubic meters. a. T b. F

A spring with a spring constant of 1200 N/m has a 55-g ball at its end. The energy of the system is 5.5J. What is the amplitude of vibration?

Force F1 acts on a particle and does work W1. Force F2 acts simultaneously on the particle and does work W2. The speed of the particle does not change. Which one of the following must be true? a. W1 is zero, and W2 is positiveb. W1 = - W2c.