Classical Mechanics Answers

Consider a hill with a slope of 30 degrees relative to the horizontal direction. I push a ball of mass 2 kg directly up the slope, and as I do so, I take ten steps, walking up the slope, with each step being 50 cm long. Presuming that the downward (i.e., vertical) force, in newtons, exerted by gravity on the ball is 9.8 times the mass of the ball in kg, by how many joules has the potential energy of the ball increased?

2 equal uniform rods AB and BC each of weight W are smoothly jointed using a light inextensible string at the vertices A and C which makes a right angle at ABC. The system is freely hinged at vertex a to a fixed point and hanging in a vertical plane. If the system is in equilibrium show that the tension in the string is 3W/2(root 5)

Four uniform smooth rods each of length to 2b and weight W are smoothly jointed had A,B,C and D to form a rhombus ABCD the system is kept in equilibrium in a vertical plane so that the rods AB and AD rest upon 2 pegs at the same horizontal level. The distance between the pegs is to 2a. The rods AB and AD each makes an angle theta to the vertical. A weight of W hangs at the lowest point C. Show that the reaction on the peg is (5Wcosec theta)/2

To win the game, a place kicker must kick a
football from a point 19 m (20.7784 yd) from
the goal, and the ball must clear the crossbar,
which is 3.05 m high. When kicked, the ball
leaves the ground with a speed of 15 m/s at
an angle of 51.7
◦
from the horizontal.
The acceleration of gravity is 9.8 m/s
2
.
By how much vertical distance does the ball
clear the crossbar?

by what method can you distinguish between a converging lens and diverging lens?

A car moves 30km/hr for 10 minutes and 50km/hr for 20 minutes. What is its average speed?

A train is on its way to deliver its cargo. The train is travelling at 90 km/h along a straight section of track. It has to cross a bridge to reach the destination. A girl is on the bridge, 2/5 of the way from the train side. The girl can just barely escape the oncoming train by running in either direction. How fast, in km/h, can the girl run? (Assume no acceleration of the girl, instantly at her constant speed.)

Express the planck radiation formula in terms of wavelength

What is the final velocity of an object that starts at rest, moves a distance of 5.0 X 10 2 m, and has an acceleration rate of 5.0 m/s2?

A charged particle q is shot towards another charged particle Q which is fixed with a speed v.it approaches Q upto a closest distance r and then returns.if q was given a speed 2v,the closest distance of approach would be