Mechanics | Relativity Answers

waves generate in a ripple tank when water is distrubted in it preodically?

A body moves 6 meter north, 8 meter east and 10 meter vertically upwards , what is the resultant displacement from initial position?

Your science teacher has assigned you the task of building a water barometer. You have
learned that the pressure of the atmosphere can vary by as much as 5% from 1 standard
atmosphere as the weather changes.
(a) What minimum height must your barometer have?
(b) One stormy day the TV weather person says, “The barometric pressure this afternoon
is a low 29.55 inches.” What is the height of the water in your barometer?

A 100 g mass on a 1.0 m long string is pulled 8.0o
to one side and released. How long does
it take for the pendulum to reach 4.0o on the opposite side?

What are the magnitude and the direction of the net gravitational force on the 20.0 kg mass?
Give the direction as an angle.

A 40 kg, 5.0 m long beam is supported, but not attached to, the two
posts. A 20 kg boy starts walking along the beam. How close can he get to the right end of
the beam without it falling over?

Susan’s 10 kg baby brother Paul sits on a mat. Susan pulls the mat across the floor using a
rope that is angled 30o above the floor. The tension is a constant 30 N and the coefficient of
friction is 0.20. Use work and energy to find Paul’s speed after being pulled 3.0 m

A 500 g rubber ball is dropped from a height of 10 m and undergoes a perfectly elastic
collision with the earth.
(a) What is the earth’s velocity after the collision? Assume the earth was at rest just before
the collision
(b) How many years would it take the earth to move 1.0 mm at this speed?

A 75 kg shell is fired with an initial speed of 125 m/s at an angle of 55o above the horizontal.
Air resistance is negligible. At its highest point the shell explodes into two fragments, one four
times more massive than the other. The heavier fragment lands directly below the point of
the explosion. If the explosion exerts forces only in the horizontal direction, how far from the
launch point does the lighter fragment land?

A 2.0 kg steel block is at rest on a steel table. A horizontal string pulls on the block.
(a) What is the minimum string tension needed to move the block?
(b) If the string tension is 20 N, what is the block’s speed after moving 1.0 m?
(c) If the string tension is 20 N and the table is coated with oil, what is the block’s speed
after moving 1.0 m?