University:
University of Colorado Boulder
Course:
PHYS 2010 | General Physics 1
Academic year:

2023
Views:

145

Pages:

2
Author:

Jeremiah Pratt

Name: Period: Key Formulas: Speed = Distance/time Velocity = Displacement/time (direction) Acceleration = (vf-vi)/time Force = mass x acceleration Momentum (p) = mass x velocity Weight = mass x gravity Problems: What is the difference between distance and displacement? Draw a picture if necessary. If I go 3 miles east, 5 miles south, and 3 miles west, what are my displacement and distance? Convert 4 days to seconds. If a train goes 52 mi/hr for 2 days, how far will it go? If a sprinter goes from 0 m/s to 8 m/s in 0.1 seconds, what is her acceleration? If you shout into the Grand Canyon, your voice travels at the speed of sound (340 m/s) to the bottom of the canyon and back, and you hear an echo. How deep is the Grand Canyon at a spot where you can hear your echo 5.2 seconds after you shout? Falling objects drop with an average acceleration of 9.8 m/s². If an object falls from a building, how long will it take before it reaches a speed of 49 m/s? What is the weight (in pounds) of a 7.0 kg bowling ball on Earth's surface? (1 kg = 2.2 lbs) What is the mass of a 7.0 kg bowling ball on the surface of the moon? 7.0 kg anywhere! What is the weight (in Newtons) of a 7.0 kg bowling ball on the surface of the moon? (Gravity on the moon is 1.6 m/s²) W = mg (7.0 kg)(1.6 m/s²) = 11 N Would a balance function correctly on the moon? Why or why not? Yes. The unknown masses would tip the scale 1/6. What is the rate of acceleration of a 2,000-kilogram truck if a force of 4,200 N is used to make it start moving forward? F = ma 4200 N = (2000 kg)(a) a = 2 m/s² How much force is needed to accelerate a 68 kg skier at a rate of 1.2 m/s²? F = ma F = (68 kg)(1.2 m/s²) F = 81.6 N What is the mass of an object that needs a force of 4,500 N to accelerate it at a rate of 5 m/s²? F = ma 4500 N = (m)(5 m/s²) m = 900 kg My friend's mass is 65 kg. What is her weight in N? W = mg (65 kg)(9.8 m/s²) = 637 N Calculate the momentum of a 11.35 kg wagon rolling down a hill at 12 m/s. p = mv p = (11.35 kg)(12 m/s) = 136.2 kg*m/s Which has more momentum: a 6,000 kg elephant napping or a 0.15 kg baseball traveling at 40 m/s? Elephant: 0 kg*m/s Baseball: (0.15 kg)(40 m/s) = 6 kg*m/s The baseball has more momentum. Which has more momentum: a 111 kg linebacker running at a speed of 5.6 m/s or an 82 kg quarterback moving at 2.5 m/s? Linebacker: (111 kg)(5.6 m/s) = 621.6 kg*m/s Quarterback: (82 kg)(2.5 m/s) = 205 kg*m/s The linebacker has more momentum.