Mechanics | Relativity Answers

The half life of a particle in the laboratory is 4×10^-8 sec,when it is speed is 0.8C what half life will be measured in the laboratory if the speed of particle is reduced 0.6C

A hydraulic braking system has been found to have a mechanical advantage of 25. In this system, what force must be exerted on the master cylinder to produce a force of 400 N on the brake cylinder

Two particle comes towards each other with a speed 0.8c with respect to the laboratory their relative speed is

A defensive lineman pushes a 550 kg quarterback 5m back at a constant velocity how much work does the line man do on the quarterback

A body of mass 0.2 kg is suspended from a spring of force constant 100 Nm^-1. The frictional force acting on it is 6v Newton, Write dow: the equation of motion and calculate the period of free oscillations. If
a harmonic force F = 20 cos 20t is applied,
calculate the amplitude of forced oscillations.

Superposition of two oscillations give Lissajous figure. State the conditions on the oscillations and nature of superposition.

A periodic force applied on a weakly damped
oscillator produces sustained oscillations. What happens to the energy supplied ?

Pls can you explain about relation between initial velocity and time t=0
Actually it is been said that initial velocity is the one which is at t=0
An example
If I watch a car moving in front of me and I start noting time , velocity etc
If I start noting velocity of car at 10.00
Am so is that 10 am is t=0 and if is yes
Then the further quest is if car was moving at 20 km /hr at 10.00 am
And at 10.01 am has 23km/hr velocity
And 10.05 am comes to rest
So what is it's initial and final velocity
Is initial velocity 20km/hr or 23km/hr
And what about final velocity is it 0
Pls clear this concept

Advances in thrill ride technologies have made electromagnetic slingshots possible instead of using large hills to propel roller coasters. Suppose a 500kg roller coaster is accelerated by a 200 kW electromagnetic motor for 4 seconds, what is its final velocity?

Two forces of 60 N east and 30 N west act on a 300kg mass. if friction is neglected, what is the resulting acceleration of the mass?