Friday

April 18, 2014

April 18, 2014

Total # Posts: 27

**Human growth and development**

Sponges, condoms, birth control, abstinence.

**Physics**

Consider a skateboarder who starts from rest at the top of a 14.6 m-long ramp that is inclined at an angle of 13.0° to the horizontal. Assuming that the skateboarder's acceleration is g sin 13.0°, find his speed when he reaches the bottom of the ramp in 3.13 s.

**physics**

Starting from rest, a ball of mass 5 kg experiences a constant force of 40 N for 12 s. What is the final kinetic energy (in J) of the ball after 12 s?

**physics**

A 64.9 kg skier coasts up a snow-covered hill that makes an angle of 25.4° with the horizontal. The initial speed of the skier is 8.67 m/s. After coasting a distance of 1.92 m up the slope, the speed of the skier is 4.33 m/s. Calculate the work done by the kinetic friction...

**physics**

A 0.620 kg basketball is dropped out of a window that is 6.40 m above the ground. The ball is caught by a person whose hands are 1.61 m above the ground. How much work is done on the ball by its weight?

**physics**

Forces of 20 N at 80 degrees, and 50 N at an angle of 210 degrees, measured counter-clockwise from the positive x-axis, act on an object. What are the components (Fx, Fy) of the resultant force (in Newtons)?

**physics**

A jogger travels a route that has two parts. The first is a displacement A of 2.30 km due south, and the second involves a displacement B that points due east. The resultant displacement A + B has a magnitude of 3.63 km. What is the magnitude of B?

**physics**

Three deer, A, B, and C, are grazing in a field. Deer B is located 61.1 m from deer A at an angle of 50.9° north of west. Deer C is located 78.4° north of east relative to deer A. The distance between deer B and C is 92.2 m. What is the distance between deer A and C?

**physics**

A 64.9 kg skier coasts up a snow-covered hill that makes an angle of 25.4° with the horizontal. The initial speed of the skier is 8.67 m/s. After coasting a distance of 1.92 m up the slope, the speed of the skier is 4.33 m/s. Calculate the work done by the kinetic friction...

**physics**

A 4.92E+2 kg hot-air balloon takes off from rest at the surface of the earth. The nonconservative wind and lift forces take the balloon up, doing +9.81E+4 J of work on the balloon in the process. At what height above the surface of the earth does the balloon have a speed of 7....

**Physics 1**

A 64.9 kg skier coasts up a snow-covered hill that makes an angle of 25.4° with the horizontal. The initial speed of the skier is 8.67 m/s. After coasting a distance of 1.92 m up the slope, the speed of the skier is 4.33 m/s. Calculate the work done by the kinetic friction...

**Physics 1**

A 0.620 kg basketball is dropped out of a window that is 6.40 m above the ground. The ball is caught by a person whose hands are 1.61 m above the ground. How much work is done on the ball by its weight?

**Physics 1**

Forces of 20 N at 80 degrees, and 50 N at an angle of 210 degrees, measured counter-clockwise from the positive x-axis, act on an object. What are the components (Fx, Fy) of the resultant force (in Newtons)?

**Physics**

A 0.0730 kg arrow is fired horizontally. The bowstring exerts an average force of 60.4 N on the arrow over a distance of 0.894 m. With what speed does the arrow leave the bow?

**Physics**

A person pulls a toboggan for a distance of 37.2 m along the snow with a rope directed 25.4° above the snow. The tension in the rope is 84.1 N. How much work is done on the toboggan by the tension force?

**Physics**

A cable lifts a 1200 kg elevator at a constant velocity for a distance of 34.5 m. What is the work done by the tension in the cable.

**Physics**

How much work (in J) is done to accelerate a car which has a mass of 3300 kg from a speed of 7 m/s to a speed of 16 m/s?

**Physics**

How much work (in J) must be done to lift a stack of bricks, which has a mass of 600 kg, from the ground to a height of 15 m? Acceleration due to gravity is 10 m/s2

**Physics**

A 61.8 kg skier coasts up a snow-covered hill that makes an angle of 26.0° with the horizontal. The initial speed of the skier is 6.10 m/s. After coasting a distance of 1.86 m up the slope, the speed of the skier is 4.48 m/s. Calculate the work done by the kinetic friction...

**Physics**

Starting from rest, a ball of mass 3 kg experiences a constant force of 21 N for 12 s. What is the final kinetic energy (in J) of the ball after 12 s?

**Physics**

Starting from rest, a ball of mass 4 kg experiences a constant force of 8 N. What is the final kinetic energy (in J) of the ball after it has traveled a distance of 1 m?

**physics**

A box which has a mass of 48 kg is dragged across the floor a distance of 5.9 m. If the coefficient of friction between the box and floor is 0.53, how much non-conservative work is done by friction? The acceleration due to gravity is 9.81 m/s2.

**Physics**

A child who has a mass of 17 kg slides down a slide from a height of 3.3 m. If friction does a non-conservative work of -143 J, what is the speed (in m/s) of the child at the bottom of the slide? The acceleration due to gravity is 9.81 m/s2

**physics**

The specific heat capacity of copper is 0.092 calories per gram per degree Celsius. How much heat is required to raise the temperature of a 5 g piece of copper from 0°C to 80°C?

**Env. Science**

Are there any helpful websites on charts that shows how U.S. spends money to help the poor in the country? You need to think about this. Some people believe helping poor is achieved by giving big business tax breaks. Recently, the Executive Office of the US has said this is th...

**social studies**

what exactly does increasing/decreasing population growth say about the country? also, if birth and death rates remain the same, what is the population pyramid going to look like in a couple of decades? It depends on who is dying. If infants are dying, it quite different than ...

**science**

If the country is not increasing in population growth rate, what are some socio/economic problems that might occur? In such a situation, the average age of the population increases and, unless there is an actuarily sound retirement funding program (instead of "pay as you ...

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