Question

1.

A 2 kg ball drops from a height of 0.5 m to the table. What will be the kinetic energy of the ball just before it hits the table? (assume g= 9.8 m/s²)

Group of answer choices

9.8 J

49.0 J

20.1 J

124 J

24.5 J

2.

Convert the velocity of 100 miles per hour into meters per second using 1 mile = 1600 meter, and 1 hour = 3600 seconds

Group of answer choices

99.9 m/s

44.4 m/s

33.3 m/s

66.7 m/s

88.9 m/s

3.

If it takes 10 seconds to raise the 0.5 kg block a vertical height of 10 m, what is the power expended? (g= 9.8 m/s²)

Group of answer choices

9.8 W

100 W

29.4 W

4.9 W

19.6 W

4.

Suppose you left a 200-W light bulb on continuously for one hour. If the electricity generation and transmission efficiency is 50%, how much chemical energy (in KJ) was transferred from the power plant?

Group of answer choices

1200 kJ

900 kJ

1440 kJ

360 kJ

1000 kJ

5.

If the world’s population is increasing at an annual rate of 1.5%, and there were 8 billion people in the year 2010, then in what year will the world’s population be 20 billion?

Group of answer choices

2093

2071

2059

2067

2089

Answer 1