A person pulls a toboggan for a distance of 35.0 m along the snow with a rope directed

$$25.0 ^ { \circ }$$

above the snow. The tension in the rope is 94.0 N. (a) How much work is done on the toboggan by the tension force? (b) How much work is done if the same tension is directed parallel to the snow?

A 75.0-kg man is riding an escalator in a shopping mall. The escalator moves the man at a constant velocity from ground level to the floor above, a vertical height of 4.60 m. What is the work done on the man by (a) the gravitational force and (b) the escalator?

A $55-\textrm{kg}$ box is being pushed a distance of $7.0 \textrm{ m}$ across the floor by a force $\vec { \mathbf { P } }$ whose magnitude is $150 \textrm{ N}$. The force $\vec { \mathbf { P } }$ is parallel to the displacement of the box. The coefficient of kinetic friction is $0.25$.

Determine the work done on the box by each of the four forces that act on the box. Be sure to include the proper plus or minus sign for the work done by each force.

A model rocket is constructed with a motor that can provide a total impulse of $29.0 \mathrm{N} \cdot \mathrm{s}$. The mass of the rocket is 0.175 kg. What is the speed that this rocket achieves when launched from rest? Neglect the effects of gravity and air resistance.

As a sailboat sails 52 m due north, a breeze exerts a constant force $\vec{\mathbf{F}}_{1}$ on the boat 's sails. This force is directed at an angle west of due north. A force $\vec{\mathbf{F}}_{2}$ of the same magnitude directed due north would do the same amount of work on the sailboat over a distance of just 47 m. What is the angle between the direction of the force $\vec{\mathbf{F}}_{1}$ and due north?

A water-skier is being pulled by a tow rope attached to a boat. As the driver pushes the throttle forward, the skier accelerates. A 70.3-kg water-skier has an initial speed of 6.10 m/s. Later, the speed increases to 11.3 m/s. Determine the work done by the net external force acting on the skier.

Match the property of A with the corresponding property of the graph of f. Assume f is differentiable. Area function A: (a) A is decreasing. (b) A has a local maximum. (c) A is concave up. (d) A goes from concave up to concave down. Graph of f: (i) Lies below the x-axis. (ii) Crosses the x-axis from positive to negative. (iii) Has a local maximum. (iv) f is increasing.

The thermal efficiency of a reversible power cycle operating between hot and cold reservoirs is $20 \%$. Evaluate the coefficient of performance of (a) a reversible refrigeration cycle operating between the same two reservoirs. (b) a reversible heat pump cycle operating between the same two reservoirs.

Find the sum of each infinite geometric series, if it exists. $\\$$0.27+0.0027+0.000027+\cdots$

Es el Año Nuevo y Ud. está trabajando en una emisora de televisión. Ud. está describiendo cómo las personas están pasando la noche en un restaurante popular. Complete las frases siguientes usando el gerundio de uno de los verbos dados (cada verbo debe usarse solamente uno vez).

comenzar                      divertirse     caer                                  tirar     tocar                                comer     celebrar                          cantar     besar                                bailar

Muchas personas siguen _______________________ serpentinas.

State the domain and range of the function.

$$f(x)=-2cos3x$$

When Paul Martinek, publisher of Lawyers Weekly USA, was a guest on the television news program The O 'Reilly Factor, he discussed a decision by a three-judge panel, chosen at random from judges in the Ninth Circuit in California. The judges had ruled that the mandatory recitation of the Pledge of Allegiance is unconstitutional because of the phrase "under God." According to Martinek, "Because there are 45 judges in the Ninth Circuit, there are 3000 different combinations of three-judge panels." Is this true? If not, what is the correct number?

Solve the equation. Check your solution.

$$- 3 = 12 y - 5 ( 2 y - 7 )$$

In the fusion of deuterium and tritium nuclei to produce a thermonuclear reaction, where does the kinetic energy that is produced come from?