Mechanics | Relativity Answers

A car of mass 1100 Kg drives with a velocity such that it
has a kinetic energy of 400 kJ ( see the Figure). Find the
velocity. If the car is raised with a carne how high
should it be lifted in the standard gravitational field (9.81 m/s2) to have a potential energy that equals the kinetic energy?

when a mass of 40 g is attached to a vertically hanging sprins it extends by 0.4 cm .find:
1 = force constant of the spring .
2 = the extension when 100 g weight is attached to it
3 = the time period of oscillation of 100 g weight on it
4 = the time period and force constant if the spring is cut in three equal parts and 100 g weight is made to oscillate on one part

a person with external body temperature 3 degree Celsius is present in a room at temperature 25 degree Celsius . assuming the emissivity of the body of the person to be 0.5 and surface area of the body of the person as 2.0 m square , calculate the radiant power of the person

A ball is thrown with a velocity of 7 root 2 m/s at an angle of 45 degree with the horizontal. It just clears two vertical poles of height 90 cm. Find the separation between the poles. Take g =9.8

You throw a ball straight up with an initial velocity of 14.3 m/s. On the way up it passes a tree branch at a height of 7.8 m. How much additional time will pass before the ball passes the tree branch on the way back down?
Numeric: A numeric value is expected and not an expression.
t = __________________________________________

Using physics concepts explain how you would lessen the force of impact as you catch a ball?

A particle of mass m is projected with velocity V making an angle of 45 degree with the horizontal. When the particle lands on the level ground the magnitude of the change in its momentum will be?
ans :- mV 1.414

A car moves towards north at a speed of 54 km/h for 1 h. Then it moves eastward with same speed for same duration. The average speed and velocity of car for complete journey is ?

A particle is revolving in a circular path of radius 25 m with constant angular speed 12 rev/min. Then the angular acceleration of particle is?
ans is zero

A projectile is fired at an angle of 45 degree with the horizontal. Elevation angle of the projectile at its highest point as seen from the point of projection is?