Mechanics | Relativity Answers

2 masses of 10kg and 20kg respectively are connected by a mass less spring which are placed vertically . A force of 200N is acting on 20kg mass at the instant when the 10kg mass has an acceleration of 12 metre per second square towards 20kg mass the acceleration of 20kg mass is

To get a flat, uniform cylindrical satellite spinning at the correct rate, engineers fire four tangential rockets. Suppose that the satellite has a mass of 4000 kg and a radius of 5.0 m , and that the rockets each add a mass of 250 kg.

What is the steady force required of each rocket if the satellite is to reach 43 rpm in 6.5 min , starting from rest?

A ball is thrown straight up with a speed of 30 m/s.
(a.) How long does it take the ball to reach the maximum height?
(b.) What is the maximum height reached by the ball?
(c.) What is its speed after 4.2 s?

A stone is thrown vertically upward with a speed of 15.0 m/s from the edge of a cliff 75.0 m high.

(a).How much later does it reach the bottom of the cliff?

(b).What is its speed just before hitting?

(c).What total distance did it travel?

Suppose our Sun eventually collapses into a white dwarf, losing about half its mass in the process and winding up with a radius 1.0% of its existing radius. Assuming the lost mass carries away no angular momentum, what would the Sun’s new rotation be? (Take the Sun’s current period to be about 30 days) What would be its final KE in terms of its initial KE of today?

Use conservation of energy to determine the angular speed of the spool shown in Figure P8.58 after the 3.00-kg bucket has fallen 4.00 m, starting from rest. The light string attached to the bucket is wrapped around the spool and does not slip as it unwinds.

Four objects are held in position at the corners of a rectangle by light rods as shown in Figure P8.37. Find the moment of iner- tia of the system about (a)thex-axis,(b)they-axis, and (c) an axis through O and perpendicular to the page

A simple pendulum consists
of a small object of mass 3.0 kg
hanging at the end of a 2.0-m-long
light string that is connected to a pivot point. (a) Calculate the magnitude of the torque (due to the force of gravity) about this pivot point when the string makes a 5.0° angle with the vertical. (b) Does the torque increase or decrease as the angle increases? Explain.

If you see an object rotating, is there necessarily a net torque acting on it?

Explain why changing the axis of rotation of an object changes its moment of inertia.