53 Answered Questions for the topic Mechanics
Kepler and Conservation of Energy
I need help wtih the following question:Consider the motion of a satellite with mass m around a planet with mass M (assume M>m). The orbit is elliptical.When the satellite is closest to the... more
Conservation of Energy
The potential energy function of a conservative force acting on an object is given by the expressionU=y-2x2-2xwhere U is in joules and x, y, z are in meters. Consider the following two points in... more
A steel strip, which has an allowable tensile stress σmax = 165 MPa is rolled up around a spool of radius R. What is the smallest value of R if the strip width b = 10 mm and the strip thickness t =... more
the periods of oscillations of n different pendulums (mathematical) are T1, T2, ..., Tn. The strings of these pendulums are joint into one without length loss and I got a new pendulum. Find its... more
Fountain physics problem
Water from a large cylinder is coming to the fountain. The cylinder has a hole of diameter d=2 cm through which the water comes up. The water is coming at a speed of 12 m/s.I need solutions for... more
Suppressive vibrations (oscillations) happen so that the amplitude of the third vibration is 11,02 times greater than the amplitude of the sixth vibration. The frequency of the vibrations is 0,5... more
Falling and bouncing ball problem
I have this interesting physics problem I can't solve. Could you please explain it in simple terms?A small ball thrown vertically down from height of 4,9 m with initial speed of 9,8 m/s hit a... more
Very hard hanging rod problem
A straight rod of 30 cm and 600 g mass is horizontally hanged on two upright, parallel and light threads, both of them attached with distances of 5 cm and 10 cm from its ends. Find tension forces... more
Spring problem .
Initial lenght of a spring is l. After hanging up a load with mass m on its end, the spring stretched doubly. Where should you hang up a load of mass 2m on now stretched spring so that after... more
A disk of mass 6 kg and radius 25 cm is rotating around horizontal axis that goes through its center with n=360 revolutions/min. When the disk was being stopped it stopped right after t=30 s.... more
Cylinder physics problem
A horizontal cylinder with volume V is filled with water and stopped up with a piston. On another end of the cylinder there is a small hole whose cross-section's area s is much smaller than the... more
Moment of inertia
Show that the moment of intertia of a solid sphere is I=(2/5)mr^2m - massr - radiusDoes here exist a non-integral solution?
Inclined plane physics problem
A sphere with mass m is put on top of an inclined plane with height h. In the first case the sphere is moving downwards without friction, and in the second case with very little friction. Find the... more
i need to solve for t
kinematic equation for physics/mechanicsd= vt + 1/2at^2
Calculate the horizontal and vertical components of a 280N force pulling upwards at an angle of 33 degrees to the horizontal
A youngster shoots a bottle cap up a 22.0o inclined board at 1.97 m/s. The cap slides in a straight line, slowing to 1.03 m/s after traveling some distance.
If the coefficient of kinetic friction is 0.36, find that distance.
A block is on an incline whose angle can be varied. The angle is gradually increased from 0o. At 34.0o, the block starts to slide down the incline.
It slides 2.9 m down the incline in 1.7 s. Calculate the coefficient of static friction. Calculate the kinetic coefficent of friction for the above problem.
Finding work done in an inclined plane
I'm trying to solve a textbook problem that says:A boy in a wheelchair (total mass 47.0 kg) has speed 1.40 m/s at the crest of a slope 2.60 m high and 12.4 m long. At the bottom of the slope his... more
Mechanics question (Vectors)
I'm really confused as to what I'm supposed to do here can someone please explain...The question is:The horizontal unit vectors i and j are in the directions east and north respectively.A model... more
Mechanics Mechanical Engineering
How do you calculate the degrees of freedom of a system?
Why are x and y equal?
This is the question I am doing:A small object is projected with speed 24 m/s from point O at the foot of a plane inclined 45 degrees to the horizontal. The angle of projection is 15 degrees above... more
Physics statics calculations
The question is : A metre rule of weight 1.0N is pivoted on a knife-edge at its centre of mass, supporting a weight of 5.0N and an unknown weight W. To balance the rule horizontally with the... more
Time taken to reach maximum height when a distress rocket is fired vertically into the air with an initial velocity of 49m/s
Its about linear motion on object moving vertically upwards
If classical physics laws fail at the quantum level , why do we still use classical physics formulas for deriving relations at an subatomic level ?
While getting a lecture on drift velocity of electrons , i came across the formula F=MA being used for electrons . also equations of motions were applied to subatomic particles . but if classical... more
Average velocity for the complete motion of the vehicle in ms-1
a motor vehicle moves half of it's path with a velocity 60ms-1 and the other half with a velocity 40ms-1. Average velocity for the complete motion of the vehicle in ms-1