Answer:
If you try to lift up a weight in a swimming pool and then try to lift the same weight on the edge of the pool, it feels much lighter in the water.
This was supposed to have been first explained by the Greek scientist Archimedes. He said that the water gives an upward force or upthrust on any object in it.
You can weigh an object in air and then in water and actually work out the upthrust, it is the difference between the two readings. For this reason the upthrust is often called the loss in weight of the object.
Answer:
0.25
Explanation:
Magnification = image distance/object distance
mag = v/u.................. Equation 1
Given: f = -10 cm ( diverging lens) u = 30 cm.
Where can calculate for the value of v using
1/f = 1/u+1/v
make v the subject of the equation
v = fv/(u-f)..................... Equation 2
Substitute into equation 2
v = -30(10)/(30+10)
v = -300/40
v = -7.5 cm.
substituting into equation 1,
mag = 7.5/30
mag = 0.25
hence the magnification of the wretch = 0.25
Given:
m = 4 kg, the mass of the object
h = 5 m, distance fallen
Neglect air resistance.
The PE (potential energy) is
PE = mgh = (4 kg)*(9.8 m/s²)*(5 m) = 196 J
The PE is converted into KE (kinetic energy) after the fall.
Therefore the PE decreased by 196 J ≈ 200 J
Answer: d. It has decreased by 200 J
Answer:
6 m/s.
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 4 m/s
Acceleration (a) = 2 m/s²
Distance (s) = 5 m
Final velocity (v) =?
The final velocity of the object can obtained as shown below:
v² = u² + 2as
v² = 4² + (2 × 2 × 5)
v² = 16 + 20
v² = 36
Take the square root of both side.
v = √36
v = 6 m/s
Therefore, the final speed of the object is 6 m/s.
