Well for starters, gravity keeps things down on Earth. Also, gravity applies its force on to cars to maintain stability by forcing the tires to make constant contact to the ground creating friction between the rubber and road surface allowing the car to be moved. I'm sure someone else has better ideas!
Answer:
if you stretch a spring with k = 2, with a force of 4N, the extension will be 2m. the work done by us here is 4x2=8J. in other words, the energy transferred to the spring is 8J. but, the stored energy in the spring equals 1/2x2x2^2=4J (which is half of the work done by us in stretching it).
Double
Explanation:
Since the period T of a pendulum is given by

By increasing the length of the pendulum by 4, the period becomes

You can see that the period doubles when we increase the length by a factor of 4.
Answer:
Three, the liquid in the man's cup, the stove is solid, and the air around them is a gas
Explanation: