The potential energy of the box when it gets to the top is
(mass) (gravity) (height)
= (7 kg) (9.8 m/s²) (5 m)
= 343 joules.
That's the work done against the force of gravity. Any
additional work is done against the force of friction.
I believe it would be 2m/s.
Answer:
The index of refraction of the glass is 1.3
Explanation:
Given data:
i = incident angle = 50°
r = refracted angle = 36.1°
The index of refraction according Snell´s law is:

Answer:
moon disappear because of the rotation
We know the formula for density = Mass/ volume
So Mass, M = Volume * Density
Volume = 3.5 L= 0.0035
Density = 1.50 g/ml = 1500 
Mass, M = 0.0035*1500 = 5.25 kg
So mass of liquid having density 1.50 g/ml and volume 3.5 liters is 5.25 kg.