1. How much kinetic energy does a 1 kg ball have if it has a velocity of 10 m/s?
Choose one answer.and explain
a. 100 J.
b. 50 J.
c. 10 J.
d. 5 J.
2. You have the grand idea that the science building would be better situated if you moved it North by 4 meters. To accomplish this you go outside and push with a 200 N against the science building for 3 hours. Needless to say, the building does not move, but you have worked up a good sweat. How much work have you done?
Choose one answer.AND EXPLAIN
a. 600 J.
b. 200 J.
c. 3.0 J.
d. 0 J.
1. The formula for kinetic energy is KE = 1/2 * mass * velocity^2. In this case, the mass of the ball is given as 1 kg and the velocity is given as 10 m/s. We can substitute these values into the formula to calculate the kinetic energy:
KE = 1/2 * 1 kg * (10 m/s)^2 = 1/2 * 1 kg * 100 m^2/s^2 = 50 J
Therefore, the correct answer is b. 50 J.
2. The equation for work is W = force * distance. In this case, the force applied is 200 N and the distance moved is 4 meters. We can substitute these values into the formula to calculate the work done:
W = 200 N * 4 meters = 800 J
However, it's important to consider that the work done should be positive if the object moves in the direction of the force. Since the science building did not move, no work was done in this case.
Therefore, the correct answer is d. 0 J.