If you stay on earth while a friend races off in a rocket at a speed close to the speed of light, then according to special relativity you will see a clock on the rocket appear to click more slowly than the one on your wall. If your friend looks back at your clock , then according to the same theory the friend will see your clock appear to tick.

A-At the same speed of the clock on the rocket
B-faster then the clock on the rocket
C-Faster or slower than the clock on the rocket, depending on the direction of travel of the rocket compared with earth
D-slower than the clock on the rocket.

D-slower than the clock on the rocket.

Explanation:

In 1905, Albert Einstein devised the theory that states that laws of physics are the same for all non-accelerating observers, and that the speed of light in a vacuum was independent of the motion of all observers. This conclusion is generally referred to as the theory of special relativity. It defined an entirely new framework for physics as well as proposed new concepts of space and time.

He discovered that space and time were interwoven into a single continuum known as space-time. According to him, events that occur at the same time for one observer could occur at different times for another, hence the answer.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards