Mastering Physics 6

A common energy unit used in food chemistry is the food calorie. 1 Cal = 1000 cal = 4186 J. What must be the inertia of a person who is moving at 1.4 m/s and has kinetic energy numerically equal to the food energy in a jelly doughnut (300 Cal)?

What can be said about the sign of the work done by the force F? 1? It is positive. It is negative. It is zero. There is not enough information to answer the question.

What can be said about the work done by force F? 2? It is positive. It is negative. It is zero.

The work done by force F? 3 is positive negative zero

The work done by force F? 4 is positive negative zero

The work done by force F? 5 is positive negative zero

The work done by force F? 6 is positive negative zero

The work done by force F? 7 is positive negative zero

Find the work W done by the 18-newton force.

Find the work W done by the 30-newton force.

Find the work W done by the 12-newton force.

Find the work W done by the 15-newton force.

Rank the joggers in order of decreasing kinetic energy. Indicate ties where appropriate.

The work W0 accelerates a car from 0 to 50 km/h. Is the work required to accelerate the car from 50 km/h to 150 km/h equal to 2W0, 3W0, 8W0, or 9W0? 8W0 2W0 9W0 3W0

Which of the following statements is true about the kinetic energy of the heavier block after the push? It is smaller than the kinetic energy of the lighter block. It is equal to the kinetic energy of the lighter block. It is larger than the kinetic energy of the lighter block. It cannot be determined without knowing the force and the mass of each block.

Now assume that both blocks have the same speed after being pushed with the same force F? . What can be said about the distances the two blocks are pushed? The heavy block must be pushed 16 times farther than the light block. The heavy block must be pushed 4 times farther than the light block. The heavy block must be pushed 2 times farther than the light block. The heavy block must be pushed the same distance as the light block. The heavy block must be pushed half as far as the light block.

A 3.00-kg ball swings rapidly in a complete vertical circle of radius 2.00 m by a light string that is fixed at one end. The ball moves so fast that the string is always taut and perpendicular to the velocity of the ball. As the ball swings from its lowest point to its highest point the work done on it by gravity is +118 J and the work done on it by the tension in the string is -118 J. the work done on it by gravity is -118 J and the work done on it by the tension in the string is +118 J. the work done on it by gravity and the work done on it by the tension in the string are both equal to -118 J. the work done on it by gravity is -118 J and the work done on it by the tension in the string is zero. the work done on it by gravity and the work done on it by the tension in the string are both equal to zero.

One kilowatt-hour represents 60 N/s. 60,000 W. 3.6 million joules. 1 N. none of these

One of the greatest difficulties with setting up the baby bouncer is determining the right height above the floor so that the child can push off and bounce. Knowledge of physics can be really helpful here. If the spring constant k=5.0×10^2N/m, the baby has a mass m=11kg, and the baby's legs reach a distance d=0.15m from the bouncer, what should be the height h of the "empty" bouncer above the floor?

If the constant force is applied for a fixed interval of time t, then the _____ of the particle will increase by an amount at.

If the constant force is applied over a given distance D, along the path of the particle, then the _____ of the particle will increase by FD.

If the initial kinetic energy of the particle is Ki, and its final kinetic energy is Kf, express Kf in terms of Ki and the work W done on the particle.

Assume that the particle has initial speed vi. Find its final kinetic energy Kf in terms of vi, M, F, and D.

What is the final speed of the particle? Express your answer in terms of Kf and M.

A 70-kg person walks at a steady pace of 5.0 km/h on a treadmill at a 5.0% grade. (That is, the vertical distance covered is 5.0% of the horizontal distance covered.) If we assume the metabolic power required is equal to that required for walking on a flat surface plus the rate of doing work for the vertical climb, how much power is required? 300 W 315 W 350 W 370 W

Based on the given data, how does the energy used in biking 1 km compare with that used in walking 1 km? Biking takes 1/3 of the energy of walking the same distance. Biking takes the same energy as walking the same distance. Biking takes 3 times the energy of walking the same distance. Biking takes 9 times the energy of walking the same distance.

How many times greater is the kinetic energy of the person when biking than when walking? Ignore the mass of the bike. 1.7 3 6 9