Questions and Answers
Calculate the distance you will travel if you maintain an average speed of 5.0 km for one-half hour.
2.5
Calculate the acceleration of a ball that starts from rest, rolls down a ramp, and gains a speed of 20 m/s in 5.0 seconds.
4.0 m/s²
Calculate the speed of a bowling ball that travels 3.8 meters in 1.6 seconds.
2.4 m/s
Calculate your average speed if you run 56 meters in 15 seconds.
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Calculate the average speed (in km/h) of Larry, who runs to the store 3.0 kilometers away in 30 minutes.
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Calculate the distance (in km) that Larry runs if he maintains an average speed of 7.1 km/h for 1 hour.
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An object is dropped from rest and falls freely. After 7.8 seconds, calculate its instantaneous speed.
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Calculate the acceleration of a 2000-kg, single-engine airplane just before takeoff when the thrust of its engine is 600 N.
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What is the momentum of a 7.8-kg bowling ball rolling at 1.2 m/s?
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What impulse occurs when an average force of 15 N is exerted on a cart for 3.0 seconds?
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What impulse occurs when the force of 10 N acts on the cart for the time 6.0 seconds?
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What is the magnitude of the impulse on a 7.0-kg ball rolling at 1.2 m/s when it bumps into a pillow and stops?
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How much impulse stops a 42-kg carton sliding at 3.6 m/s when it meets a rough surface?
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A 1.0-kg blob of putty moving at 2.4 m/s slams into a 1.0-kg blob of putty at rest. Calculate the speed of the two stuck-together blobs of putty immediately after colliding.
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Calculate the work done when a force of 1.2 N moves a book 2.1 m.
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Calculate the work done in lifting a 580-N barbell 1.4 m above the floor.
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Calculate the watts of power expended when a force of 2.4 N moves a book 3.0 m in a time interval of 1.0 s.
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Calculate the increase in potential energy when an 18-kg block of ice is lifted a vertical distance of 1.2 m.
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Calculate the kinetic energy of a 3.4-kg toy cart that moves at 4.4 m/s.
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What change in kinetic energy does an airplane experience on takeoff if it is moved a distance of 560 m by a sustained net force of 4400 N?
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What is his kinetic energy when his potential energy reduces to 1000 J?
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If you pull one end of the rope 1.3 m downward with a 52-N force, find the height you can lift a 240-N load.
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How many watts of power do you expend when you exert a force of 0.80 N that moves a book 2.3 m in a time interval of 1.1 s?
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Calculate the torque produced by a 46-N perpendicular force at the end of a 0.17-m long wrench.
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Calculate the torque produced by a 58-N force when a pipe extends the length of the wrench to 0.44 m.
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Calculate the tension in a horizontal string that whirls a 2.4-kg toy in a circle of radius 2.6 m when it moves at 3.3 m/s on an icy surface.
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Calculate the force of friction that keeps a 60-kg person sitting on the edge of a horizontal rotating platform when the person sits 2.1 m from the center of the platform and has a tangential speed of 3.6 m/s.
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Calculate the angular momentum of the person if the force of friction that keeps a 65-kg person sitting on the edge of a horizontal rotating platform when the person sits 1.7 m from the center of the platform and has a tangential speed of 3.6 m/s.
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Calculate the force of gravity on a 1-kg mass at Venus's surface. The mass of Venus is 4.9×10²⁴ kg, and its radius is 6.1×10⁶ m.
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Calculate the force of gravity between Earth (mass = 6.0×10²⁴ kg) and the Sun (mass = 2.0×10³⁰ kg). The average Earth-Sun distance is 1.5×10¹¹ m.
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Suppose you do 100 J of work in compressing a gas. If 80 J of heat escapes in the process, what is the change in internal energy of the gas?
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Study Notes
Distance and Speed Calculations
- To calculate distance: Distance = Average Speed × Time. Example: traveling at 5.0 km/h for 0.5 hours results in a distance of 2.5 km.
- Calculate the speed with: Speed = Distance / Time. Example: a bowling ball traveling 3.8 m in 1.6 s has a speed of 2.4 m/s.
- Average speed can be derived from total distance over time: for running 56 m in 15 s, average speed is 3.7 m/s.
Acceleration and Free Fall
- Acceleration can be calculated as: Acceleration = (Final Speed - Initial Speed) / Time. For a ball rolling down at 20 m/s in 5 s, the acceleration is 4.0 m/s².
- For an object in free fall, after 7.8 s, the instantaneous speed is calculated to be 78 m/s.
Momentum, Impulse, and Collision
- Momentum is determined by the formula: Momentum = Mass × Velocity. Thus, a 7.8-kg bowling ball moving at 1.2 m/s has a momentum of 9.4 kg·m/s.
- Impulse occurs when force is applied over time, calculated as: Impulse = Force × Time. An average force of 15 N over 3.0 s results in an impulse of 45 kg·m/s.
Work and Energy
- Work done can be calculated using: Work = Force × Distance. Moving a book with a 1.2 N force for 2.1 m results in 2.5 Joules of work.
- Potential energy increase when lifting an object can be calculated: lifting an 18-kg block a height of 1.2 m results in a potential energy increase of 220 Joules.
Power and Efficiency
- Power is determined by the formula: Power = Work / Time. For moving a book with a force of 2.4 N over 3.0 m in 1.0 s, power expended is 7.2 Watts.
- Further examples show how power varies with the force and distance moved over time.
Torque and Circular Motion
- Torque is calculated by: Torque = Force × Distance (perpendicular). A 46-N force over a 0.17 m wrench produces a torque of 7.8 Nm.
- Tension in a circular motion example: a 2.4-kg toy moving in a circle at 3.3 m/s has a tension in the string of 10 N.
Gravitation and Force Calculations
- Gravitational force on a 1-kg mass at Venus’ surface is 8.8 N based on its mass and radius.
- The gravitational force between the Earth and the Sun is calculated to be significant at 3.6 × 10²² N.
Energy Changes
- Calculating changes in internal energy using work and heat: compressing gas with 100 J of work and 80 J heat escape results in a change of 20 Joules in internal energy.
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Description
Test your knowledge on fundamental concepts of physics including distance, speed, acceleration, and momentum. This quiz covers key formulas and practical examples to help reinforce your learning. Ideal for students in physics classes.