The force required to hold a water hose

Calculate the force required to hold a water hose of radius 0.04 m when it emits a jet of water at a speed of 20 m/s.

Continue reading

The stones in the container

smallStonesA vertical container (right rectangular prism) with base area measuring 0.15 m by 0.2 m is being filled with identical small stones, each with a volume of 2*10-8 m3 and a mass of 0.05*10-3 kg. Assume that the volume of the empty spaces between the stones is negligible. If the height of the stones in the container increases at the rate of 3*10-3 m/s, at what rate does the mass of the stones in the container increase?
 
Continue reading

A yacht drops anchor

yacht

A yacht drops its anchor overboard. What happens to the water
level?

Continue reading

A ball fell into a vessel

BallVessel A wooden ball fell into a high cylindrical vessel. The diameter of the vessel and the diameter of the ball is 5 cm and 4 cm respectively. Can you get the ball without touching the vessel?

 

Continue reading

Which of the following is a mixture?

Which of the following is a mixture?
a) water
b) carbon-dioxide
c) methane
d) coffee with milk
e) air
f) salt
g) brass
h) sugar
i) mayonnaise
j) none of the above
k) all of the above

Continue reading

What is the density of the material from which the object is made?

2Liq

 

In the vessel are two immiscible liquids with densities ρ1 and ρ2 and layers of thickness h1 and h2 respectively. From the surface of liquid is lowered a streamlined object which reaches the bottom right at the moment when its speed becomes zero. What is the density of the material from which the object is made?

Continue reading

A lake on the moon with a boat on it…

LakeBoat

Since gravity is much weaker on the moon, everything weigh only 1/6 of its Earth-weight. Imagine there is a lake on the moon with a boat on it…
This boat has a draft of 1 meter in terrestrial freshwater lakes.
How deep will sit the boat in the water of the moon lake?

Continue reading