How much force needs to be applied when 800J of work causes a resting 40kg Block to slide 4m over a Frictionless surface? What will the Velocity be at the end of 4m?

v = 6.32 [m/s]

Explanation:

We know that work in physics is defined as the product of force by distance, in this way we have:

where:

F = force [N]

W = work [J]

d = distance = 4 [m]

Now we know that by means of Newton's second law which tells us that the total force on a body is equal to the product of mass by acceleration, we can determine the acceleration that occurs.

where:

F = force = 200 [N]

m = mass = 40 [kg]

a = acceleration [m/s²]

Now using this equation of kinematics we can determine the final velocity.

where:

vf =  final velocity [m/s]

vo = initial velocity = 0 (initially at rest)

a = acceleration = 5 [m/s]

x = distance = 4 [m]

b.

hope this : )

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.