KE = (1/2) (mass) (speed)²
KE = (1/2) (20 kg) (40 m/s)²
KE = (1/2) (20 kg) (1,600 m²/s²)
KE = (10 kg) (1,600 m²/s²)
KE = 16,000 Joules
The second one if it’s on edge
Incomplete question as the unit of volume is not written correctly.So the complete question is here:
A straightforward method of finding the density of an object is to measure its mass and then measure its volume by submerging it in a graduated cylinder. What is the density of a 240-g rock that displaces 89.0 cm³?
Answer:

Explanation:
Given data
Mass m=240g
Volume V=89.0 cm³
To find
Density d
Solution
If rock displaces 89.0 cm³ of water means volume of rock is also 89cm³
So

B. opposite charge and smaller mass
Answer:
<em>W=700 Joule</em>
Explanation:
<u>Physics Work
</u>
Is the dot product of the force vector by the displacement vector

When both the force and the displacements are pointed in the same direction, the formula reduces to its scalar version

The weightlifter is applying a net force of 350 N to lift the weights a distance of 2 m, thus the net work done is
