Question 1

A car moves along a straight road. Its position as a function of time is given by $$x(t) = 3t^2$ + 2t + 1$$, where $$x is in $$meters and $$t is in $$seconds. What is the car's acceleration at $$t = 2 s$$?

Accepted Answer

$$a = 6 m/s$^2$$

Question 2

A projectile is launched from ground level with an initial velocity of $$v_0 = 20$ m/s at an angle of 30$$^\	ext{o}$$ above the horizontal. What is the maximum height reached by the projectile? (Assume g = 9.8$ m/s^2$)

Accepted Answer

$$h_{	ext{max}} = 10.2 m$$

Question 3

A ball is whirled in a horizontal circle of radius $$r = 0.5 m at a $$constant speed of $$v = 4 m/s. $$What is the magnitude of its centripetal acceleration?

Accepted Answer

$$a_c = 16 m/s$^2$$

Question 4

A 5 kg box is pulled horizontally with a force of 20 N. If the coefficient of kinetic friction between the box and the floor is $$\mu_k = 0.3$$, what is the acceleration of the box? (Assume $$g = 9.8 m/s$^2)$$

Accepted Answer

$$a = 0.8 m/s$^2$$

Question 5

Two ice skaters push off from each other on a frictionless surface. Skater A has mass 60 kg and skater B has mass 40 kg. If skater A moves at 3 m/s after the push, what is skater B's velocity?

Accepted Answer

$$v_B = -4.5 m/s$$

Question 6

A 2 kg object moving at 5 m/s collides elastically with a stationary 3 kg object. What is the velocity of the 2 kg object after the collision?

Accepted Answer

$$v = -1 m/s$$

Question 7

A solid disk of mass $$M = 2 kg $$and radius $$R = 0.5 m $$rotates about its center. What is its moment of inertia?

Accepted Answer

$$I = 0.25 kg$$\cdot$$ m^2$

Question 8

A wheel of radius $$0.4 m $$accelerates from rest to an angular velocity of $$10$$ rad/s in $$2$$ seconds. What is its angular acceleration?

Accepted Answer

$$\alpha = 5$$ rad/s$$^2$$

Question 9

A uniform rod of length $$L = 1 m $$and mass $$m = 3 kg is $$pivoted at one end. What is its moment of inertia about the pivot?

Accepted Answer

$$I = 0.75 kg$$\cdot$$ m^2$

Question 10

A spring with spring constant $$k = 200 N/m is $$compressed by $$x = 0.1 m. $$What is the potential energy stored in the spring?

Accepted Answer

$$U = 0.5 J$$

Question 11

A block of mass $$2 kg $$slides down a frictionless incline from a height of $$5 m. $$What is its speed at the bottom?

Accepted Answer

$$v = 10 m/s$$

Question 12

A gas in a cylinder undergoes an isothermal expansion at $$T = 300 K. If $$the initial volume is $$0.5 m$^3$$ and the final volume is $$1.0 m$^3$$, what is the work done by the gas? (Assume $$n = 2$$ mol, $$R = 8.31 J/$$mol\cdot K)

Accepted Answer

$$W = 1037 J$$

Question 13

A refrigerator removes $$500 J of $$heat from its interior and expels $$800 J to $$the kitchen. What is the work input required?

Accepted Answer

$$W = 300 J$$

Question 14

A heat engine absorbs $$1000 J of $$heat from a hot reservoir and expels $$600 J to a $$cold reservoir. What is its efficiency?

Accepted Answer

$$e = 0.4$$

Question 15

A $$0.5 kg $$mass attached to a spring oscillates with a period of $$2 s. $$What is the spring constant $$k$$?

Accepted Answer

$$k = 4.93 N/m$$

Question 16

A $$0.2 kg $$mass is attached to a string and swung in a circle of radius $$0.6 m at a $$speed of $$3 m/s. $$What is the tension in the string?

Accepted Answer

$$T = 3 N$$

Question 17

A $$1 kg $$block is pushed against a spring (with $$k = 100 N/m) $$compressing it by $$0.2 m. $$The block is released and slides across a frictionless surface. What is its speed as it leaves the spring?

Accepted Answer

$$v = 4 m/s$$

Question 18

A $$0.3 kg $$mass is attached to a spring with $$k = 12 N/m $$and oscillates with amplitude $$0.1 m. $$What is the maximum speed of the mass?

Accepted Answer

$$v_{	ext{max}} = 0.63 m/s$$

Question 19

A $$0.5 kg $$block at $$20^	ext{o}C $$absorbs $$1000 J of $$heat. If the specific heat of the block is $$c = 500 J/kg$$\cdot K, what is its final temperature?

Accepted Answer

$$T_f = 24^	ext{o}C$$

Phys 2425: Physics with Calculus – Course Syllabus and Topic Overview

Study Guide - Practice Questions

Study Guide - Flashcards