Q: A gold bar has a density of $$19.3\ \mathrm{g/cm^3$}. $$What is its density in $$\mathrm{kg/m^3$}$$?

$$1.93 \times 10^4$\ \mathrm{kg/m^3$}$$

Q: A 75-kg climber moves from an elevation of $$1500\ \mathrm{m} to$$ $$2400\ \mathrm{m}. $$What is her change in gravitational potential energy? ($$g=9.80\ \mathrm{m/s^2$})$$

$$6.62 \times 10^5$\ \mathrm{J}$$

Q: A person sings a $$466\ \mathrm{Hz}$$ note. What is the time for one cycle and the angular frequency of the vocal cords?

$$2.15 \times 10$$^{-3}$$\ \mathrm{s}$$, $$2.93 \times 10^3$\ \mathrm{rad/s}$$

Question 1

A gold bar has a density of $$19.3\ \mathrm{g/cm^3$}. $$What is its density in $$\mathrm{kg/m^3$}$$?

Accepted Answer

$$1.93 	imes 10^4$\ \mathrm{kg/m^3$}$$

Question 2

A seabird is released 5150 km from its nest and returns in 13.5 days. What is its average velocity in $$\mathrm{m/s}$$ for the flight?

Accepted Answer

$$4.42\ \mathrm{m/s}$$

Question 3

A rock is thrown upward at $$22.0\ \mathrm{m/s}$$ from the top of a $$30.0\ \mathrm{m}$$ building. What is its speed just before it hits the street below? (Assume $$g=9.80\ \mathrm{m/s^2$})$$

Accepted Answer

$$32.7\ \mathrm{m/s}$$

Question 4

A coin is tossed at $$6.4\ \mathrm{m/s} at a$$ $$60^\circ$$ angle and lands in a dish $$2.1\ \mathrm{m}$$ away (horizontally). What is the height of the shelf above the ground?

Accepted Answer

$$0.98\ \mathrm{m}$$

Question 5

Two dogs pull on a post at a $$60.0^\circ$$ angle with forces of $$270\ \mathrm{N}$$ and $$300\ \mathrm{N}. $$What is the magnitude of the resultant force?

Accepted Answer

$$517\ \mathrm{N}$$

Question 6

A 180-kg piano slides at constant velocity down a $$19.0^\circ$$ ramp. What force must a man apply parallel to the incline to maintain this motion?

Accepted Answer

$$573\ \mathrm{N}$$

Question 7

A 1.50-kg book slows from $$3.21\ \mathrm{m/s} to$$ $$1.25\ \mathrm{m/s} on a $$rough surface. What is the total work done on the book?

Accepted Answer

$$-6.36\ \mathrm{J}$$

Question 8

A 75-kg climber moves from an elevation of $$1500\ \mathrm{m} to$$ $$2400\ \mathrm{m}. $$What is her change in gravitational potential energy? ($$g=9.80\ \mathrm{m/s^2$})$$

Accepted Answer

$$6.62 	imes 10^5$\ \mathrm{J}$$

Question 9

A 70.0-kg person on frictionless ice catches a $$0.600-kg $$ball thrown at $$10.0\ \mathrm{m/s}. $$What is their final speed?

Accepted Answer

$$0.085\ \mathrm{m/s}$$

Question 10

A 2.80-kg solid cylinder (radius $$0.100\ \mathrm{m}) $$starts from rest. What torque is required to reach $$1200\ \mathrm{rev/min} in$$ $$2.5\ \mathrm{s}$$?

Accepted Answer

$$2.11\ \mathrm{N \cdot m}$$

Question 11

A 50.0-cm bar (0.120 kg) has masses of 0.055 kg and 0.110 kg at its ends. Where should the fulcrum be placed to balance it horizontally (measured from the 0.055 kg mass)?

Accepted Answer

$$0.36\ \mathrm{m}$$

Question 12

A 950-kg cylindrical buoy (diameter $$0.900\ \mathrm{m}) $$floats in the sea. How much further does it sink when an 80.0-kg man stands on it?

Accepted Answer

$$0.13\ \mathrm{m}$$

Question 13

Given Venus has 81.5% Earth's mass and 94.9% its radius, what is the acceleration due to gravity on its surface? ($$g_{Earth} = 9.80\ \mathrm{m/s^2$})$$

Accepted Answer

$$8.87\ \mathrm{m/s^2$}$$

Question 14

A person sings a $$466\ \mathrm{Hz}$$ note. What is the time for one cycle and the angular frequency of the vocal cords?

Accepted Answer

$$2.15 	imes 10$$^{-3}$$\ \mathrm{s}$$, $$2.93 	imes 10^3$\ \mathrm{rad/s}$$

Question 15

A 1.50-m rope has a wave speed of $$62.0\ \mathrm{m/s}. $$What is the frequency of the fundamental mode?

Accepted Answer

$$20.7\ \mathrm{Hz}$$

Question 16

A 3.00-N rock is moving at $$25.0\ \mathrm{m/s}$$ when it reaches $$15.0\ \mathrm{m}$$ above the ground. Using the work-energy theorem, what was its initial speed if it was thrown upward from ground level?

Accepted Answer

$$33.2\ \mathrm{m/s}$$

Question 17

A 2.00-m steel wire must stretch no more than $$0.25\ \mathrm{cm}$$ under a $$700\ \mathrm{N}$$ force. If Young's modulus for steel is $$2.00 	imes 10$$^{11}$$\ \mathrm{N/m^2$}$$, what is the minimum diameter required?

Accepted Answer

$$2.99\ \mathrm{mm}$$

Question 18

A rocket burns $$0.0500\ \mathrm{kg/s} of $$fuel and ejects it at $$1600\ \mathrm{m/s}$$ relative to the rocket. What is the thrust produced?

Accepted Answer

$$80.0\ \mathrm{N}$$

Question 19

A machinist applies a $$17.0\ \mathrm{N}$$ force to a $$25.0\ \mathrm{cm}$$ wrench at a $$37^\circ$$ angle. What is the torque exerted on the nut?

Accepted Answer

$$3.45\ \mathrm{N \cdot m}$$

Physics I: Core Concepts and Problem-Solving Guide

Guida di studio - Domande di pratica

Study guide - Flashcard