Mechanics | Relativity Answers

The distance between two telephonepoles is 50.0 m. When a 1.00-kg bird lands on the telephone wire midway between the poles,the wire sags 0.200 m. (a) Draw a free-body diagram of the bird. (b) How much tension does the bird produce in the

wire? Ignore the weight of the wire.

A block slides down a frictionless plane having an inclination of 0 = 15.0°. The block starts from rest at the top, and the length of the incline is 2.00 m. (a) Draw a free-body diagram of the block. Find (b) the acceleration of the blockand (c) its speed when it reaches the bottom of the incline

Review, Three forces acting on an object are given by F1=

(-2.001 + 2.00j) N, and F2 = (5.001 - 3.00j) N, and F3=

(-45.01) N. The object experiences an acceleration of mag-

nitude 3.75 m/s?. (a) What is the direction of the accelera-

tion? (b) What is the mass of the object? (c) If the object is

initially at rest, what is its speed after 10.0 s? (d) What are

the velocity components of the object after 10.0 s?

Acceleration of earth around sun in its orbit is always

a tengential b radial

0/60km in9.7sec what is the acceleration

a.      The helicopter lifts the vehicle of mass 1500 kg at a vertical acceleration of 3.0 m s–2. Show that the tension in the cable is 1.9 ´ 104 N.

At a later time, the helicopter is moving forward in level flight at a constant velocity of 50 m s–1. The cable carrying the vehicle now hangs at a steady angle of 15°  to the vertical as shown in the diagram below.

b.     Draw labelled arrows on the diagram to show and name the forces acting on the vehicle.

c.      Calculate the tension in the cable in this case.

d.     Calculate the size of the drag force on the car.

If you miss a brick on the way up,during what remaining time interval can you reach out and catch the brick on its way down

Calculate the divergence and Curl, of the following functions

a. V= x2 i+3xy^

2

j -2xyz k

b. V=xyi+2yz j+3zx k

c. V= y2

i +(2xy+z2

)j+ 2yz k , where i , j , k are unit vectors along x, y and z axis

An object falls 10.0m from rest before entering some water. Assuming negligible air resistance, what is the time taken to reach the water and the speed with which the object reaches the water? time/ ms speed/ ms–1 A 1.02 10.0 B 1.02 14.0 C 1.43 10.0 D 1.43 14.0