Mechanics | Relativity Answers

A 13.7-kg box is being pushed from the bottom to the top of a frictionless ramp. When the box is pushed at a constant velocity, the nonconservative pushing force does 58.0 J of work. How much work is done by the pushing force when the box starts from rest at the bottom and reaches the top of the same ramp with a speed of 1.50 m/s?

A force does +210 J of work when it acts on a moving object and its direction is in the same direction as the object’s displacement. How much work does this force do when the angle between it and the object’s displacement is 56°?

A pendulum has a period of 1.8 s.

The original pendulum is taken to a planet where g = 16 m/s2.

What is its period on that planet?

A train travelling along a straight track starts from rest at point A and accelerates uniformly to 20 m/s in 20 second. it travels at this speed for 60 second, then slows down uniformly to rest in 40 second at point c. it stays at rest at this speed for 30 second, then slowls down uniformly to rest in 10 second when it reaches point B.
a.plot a graph of the motion of the train
b.use your graph to calculate
i.The train displacement from A when it reaches point C
ii.The train's displacement from A when it reaches point B
iii.The trains acceleration each time its speed changes

Find the percentage decrease in weight of body whem taken to a height of 32 km above the surface f earth. Radius of earth is given as 6400 km.

Suppose you roll a disk up a slope with an initial velocity v=17m/s at a 33 degree angle. When will it come to rest?

you plan a trip on which you want to average 90.0km/h. you cover the first half of your distance at an average speed of only 48km/h. what type of vehicle must you use in order to meet your goal? Note that the velocities are based on half the distance not half the time

A 0.75-kg metal sphere oscillates at the end of a vertical spring. As the spring stretches from 0.12 m to 0.23 m (relative to its unstrained length), the speed of the sphere decreases from 6.7 to 3.2 m/s. What is the spring constant of the spring?

a peny dropped from the top of a rollercoaster.the height of the ride is 110m.(neglect air resistance)
A.find the speed of the penny when it hits the ground.
B.find the time it takes for the penny to fall to the ground.

A litre of whole milk has a mass of 1032 g. It contains 4% butterfat by volume. The
specific gravity of butterfat is 0.865 g/cc. What is the density in g/cc of the fat free
“skimmed-milk”?