A 1000 kg car whose speed is 80 km/h (22.2m/s) has how much kinetic energy?
A. 247 kJ
B. 3.2 MJ
C. 25.2 kJ
D. 2.42 MJ
A gold ball and a ping-pong ball are dropped in a vacuum chamber. When they have fallen down, they have the same?
A. Kinetic energy
B. Rest energy
C. Potential energy
￼What never changes when two or more objects collide?
A. The total momentum of all the objects
B. The kinetic energy of each object
C. The momentum of each object
D. The total kinetic energy of all the objects
What is the mass of an object moving with respect to us?
A. Always greater than its rest mass
B. Always less than it’s rest mass
C. Less than it’s rest mass when it moving towards us and greater than it’s read mass when it is moving away from us
D. Greater th￼an it’s rest mass then it is moving towards us and less than it’s rest mass when it is moving away from us
Arrange the following sources in the order of the amount of energy they supplied in 2003 to the world.
A. Oil,natural gas coal,uranium
B. Oil, coal, uranium, natural gas
C. Coal,oil,uranium, natural gas
D. Oil, coal, natural gas, uranium
You can believe scientists, especially when they talk about environmental concerns because…
A. Scientist never care about money. ￼
B. Scientist always agree.
C. Scientist are never￼ prejudiced.
D. None of these
E. Scientist are always right.