Mechanics | Relativity Answers

A crate weighing 80N is pulled along a horizontal surface by a force of 15 N which is applied 20° above the horizontal. If the crate from rest and the coefficient of friction is 0.15, determine the kinetic energy and the velocity of the crate after it has moved a distance of 10 m.

you are working as a letter sorter in the Post office. Postal regulations require that employees' footwear must have a minimum coefficient of static friction of 0.5 on a specified tile surface. You are wearing athletic shoes for which you do not know the coefficient of static friction. In order to determine the coefficient, you imagine that there is an emergency and start running across the room. You have a co-worker time you, and find that you can begin at rest and move 4.23 m in 1.20s. If you try to move faster that this, your feet slip. Assuming your acceleration is constant, does your footwear qualify for the postal regulation?

A boy tosses a ball straight up with an initial velocity of 13.0m/s a)how long does the ball take to reach its highest point? B)how high does the ball rise above it's realise point

A speedboat sends out a wave that rocks a small boat where a senior high school student is standing. She notices that the height of the wave as measured from trough to peak is 0.60 m and that the wave rocks the small boat with a period of 2.0 s. The distance between crests is 1.9m. What are the amplitude,wavelength,the frequency,wave speed, wave number angular frequency ,wave function and the maximum vertical speed of the rowboat

 Calculate the work done by a 2.4 N force pushing a plate across a table 0.75 m wide.

A particle moves under a force for which the potential energy is shown in the figure. It has a total energy of U_o. The particle cannot be found in the range

An object is acted upon by two forces 20N each .The angle between the forces is 120 degrees.The resultant force on the object has the magnitude of what

A diver of mass 65 kg takes off from the 10 m platform from a standing position by jumping upwards with a (near) vertical speed of 2.0 ms^-1 at a speed of 30mph.

Sketch graphs of displacement against time and velocity against time for the dive, pointing out the important features of the graphs and the relationship between the two graphs.

A fan motor uses 6630 J of energy in 8.80 s. This energy is used to accelerate a 12.9 kg blade to 26.5 m

s

ms in 7.75 s. What is the efficiency of the fan? Leave your answer as a decimal.

A 112 kg stone boulder rolls down a 67.8 m long ramp with an angle of inclination of 27.7° in 10.3 s. What is the power of gravity on the boulder?