While skiing, Ellen encounters a ledge that sends her flying horizontally at a rate of 12 m/s. How far away will she land if the ledge is 7 meters high? ...?

Answer:

1)the unit of work is joule. 2)it is derived unit because it is made by two different unit force and displacement .3)

Answer:

The volume of the object = 0.0203 m³

Explanation:

From Archimedes principle,

Upthrust = lost in weight = amount of water displaced.

U = W₁ - W₂

Where U = upthrust, W₁ = Weight in air, W₂ = weight in water.

U = 930- 731

U = 199 N.

but mass of water displaced,

m = U/g where g = 9.8 m/s²

m = 199/9.8

m = 20.31 kg.

Recall,

Density = mass/volume.

Density of water = mass of water displaced/ volume of water displaced

D = m/V

V = m/D......................................... Equation 1

Where V = volume of water displaced, m = 20.31 kg, D = 1000 kg/m³

Substitute into equation 1

V = 20.31/1000

V = 0.0203 m³

the volume of water displaced = 0.0203 m³

Note: That when an object is immersed in water, the volume of water it displaced is equal to it's volume.

Hence, Volume of water displaced = volume of the object.

Hence the volume of the object = 0.0203 m³

Answer:

6 m/s

Explanation:

At constant acceleration, the final velocity is equal to the initial velocity plus the product of time and acceleration:

v = at + v₀

We know that at t=2, v=12.  And at t=4, v=18.

12 = 2a + v₀

18 = 4a + v₀

We can solve the system of equations for v₀.  If we double the first equation:

24 = 4a + 2v₀

And subtract the second:

24-18 = 4a-4a + 2v₀ - v₀

6 = v₀

The initial velocity is 6 m/s.

Answer:

V = -39.2m/s

Explanation:

Given the following data

Time, t = 4secs

Since the rock is falling, we know that the initial velocity = 0

Acceleration due to gravity = 9.8m/s²

To find the final velocity, we would use the first equation of motion

V = U + at

Substituting into the equation, we have

V = 0 + (-9.8*4)

V = -39.2m/s