What is the approximate efficiency of the engine? A heat engine has a temperature of 1800 K. Some of the
heat from the engine flows to the surroundings, which
are at a temperature of 160 K.
0 16%
O 91%
O 103%
O 109%

concave lenses are used here. they spread the light out before it reaches the convex lens in the eye, therefore letting the image focus directly on the retina. hyperopia is known to you probably as farsightedness.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.