Why gravitational force at the center og earth is zero

A skydiver is falling at 50 m/s when they open their parachute. The parachute slows them at a rate of 4 m/s^2 until they reach terminal velocity of 3 m/s. How long does it take to reach terminal velocity?

A 1200 Kg car rounds a corner of radius r = 45m. If the coefficient of static friction between the ties and the road is us = 0.82, what is the greatest speed the car can have in the corner without skidding?

Which landform represents the boundary between the land and an ocean or a lake?

A box is initially at rest on a frictionless inclined plane

Which electromagnetic wave type has the largest wavelength?

Describe the factors that form deep currents

A comet is cruising through the solar system at a speed of 50000 kilometers per hour for 4 hours time. What is the total distance traveled by the comet during this time in kilometers, miles, and light years?

A gas in a closed container is heated with 12J of energy, causing the lid of the container to rise 3m with 5N of force. What is the total change in energy?

What are illuminated objects?

During one year a population of blue jays has zero population growth. which must be true about the blue jay population at the end of the year compared to the beginning of the year?