A tractor pulls on a tree for 3 minutes with a force of 100 pounds. The tree does not move. How much work is done?

1000 ft-lbs

3000 ft-lbs

unknown

zero

Would you expect the air pressure in a valley thats below sea level to be higher or lower than the air pressure at sea level

2. Why does the potential energy decrease as the ball falls?

A car with a mass of 1.50x10^3 kg starts from rest and accelerates to a speed of 18.0m/s in 12.0 s. assume that the force of resistance remains constant 400.0n during this time. what is the average power developed by the car's engine.

Which of the following are thought to be rapidly rotating neutron stars with intense magnetic fields? Choose one answer. a. pulsars b. white dwarfs c. black holes d. flare stars e. accretion disks

A 0.3 mm long invertebrate larva moves through 20oC water at 1.0 mm/s. You are creating an enlarged physical model of this larva so you can better study its flow pattern in the laboratory.

Which characteristics are used to identify types of metamorphic rocks? Check all that apply. color foliation rock size grain arrangement type of rock before metamorphosis

What is the current in a 120V circuit if the resistance 10?

What factor causes the seasons? A: Rotation of earth's axis B: The tilt of earth's axis with respect to the sun C: The appearance of the moon D: An eclipse

A golfer on a level fairway hits a ball at an angle of 21° to the horizontal that travels 99 yd before striking the ground. He then hits another ball from the same spot with the same speed, but at a different angle. This ball also travels 99 yd.

What's earths most precious element?