(d) You observe someone pulling a block of mass 40 kg across a low-friction surface. While they pull a distance of 4 m in the direction of motion, the speed of the block changes from 5 m/s to 6 m/s. Calculate the magnitude of the force exerted by the person on the block. F

55 N

Explanation:

We find the acceleration of the block. The velocity changed from 5 m/s to 6 m/s in a distance of 4 m. We use the equation of motion:

and v are the initial and final velocities, a is the acceleration and s is the distance.

The force exerted on the block, assuming no friction, is

d eras and periods

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.