Thermal conductivity comparison

Which of the following cylindrical rods of the same material with its ends at the same steady difference of temperature will conduct maximum heat ? 1. Lenght 100 cm & radius 1 cm 2. length 200 cm & radius 1 cm 3. length 400 cm & radius 2 cm 4. length 100 cm & radius 2 cm

Lactometer: finding graduations

Two graduations on the stem of a lactometer are 0.6 and 0.9. Find the graduation exactly midway between them.

Driving at night: Safe speed

Explain how the range of a car's headlights limits the safe driving speed at night

Whirling stone: Maximum velocity

A man whirls a stone round his head on the end of a string 2 m long. Can the string be in a horizontal plane ? If the stone has a mass of 200g and the string will break if the tension exceeds 4 Newton, what is the smallest angle the string can make with the horizontal ? What is then the speed of the stone ? Take g = 10m/s^2

An object is held stationary by a cable near the sea floor. Find the cable tension.

An apparatus consisting of a wood block of density 650 kg/m^3 and mass M= 64 kg, is attached by a cable to a cement block of density 4500 kg/m^3 and mass 125 kg. The cement block rests on the sea bottom, and holds the wood block stationary above it. The sea density is 1025 kg/m^3. Find the tension in the cable.

A body in free fall vertically, find maximum height and time of flight.

A rock is thrown upward from ground level with initial upward velocity of 25 m/sec. The rock falls back down into a hole and strikes the bottom 35 meters below the ground surface. Find the maximum height reached and the total flight time.

From a roof, one object dropped. Later another thrown down. Both hit at the same time. find height of building.

From a rooftop, a rock is released at rest and 2 seconds later, a marble is thrown downward from the roof with initial speed of 24.5 m/sec. Both hit the ground at the same instant. Find the height of the building.

A rock is thrown upward from the ground. Find the change in height during a certain time interval.

A rock is given initial upward velocity of 49 m/sec at ground level. Find the change in height in the last 1.5 seconds of its upward motion.

Given a graph of x(t) with two known points, develop x(t).

A moving point has constant acceleration along an x axis. The graph shown as ATTACHMENT #1 shows the graph with certain known information listed. Find the equation of the line, x(t), from the given known points.

Two spacecrafts approaching each other, pass each other twice. Find the times and locations of each passing.

Spacecraft A is initially 120 m from spacecraft B, moving towards each other on parallel paths. Both spacecrafts apply reverse thrust to reverse their motion after which they meet twice. Spacecraft A has initial velocity VoA= +25 m/sec and acceleration aA= -3 m/sec^2. Spacecraft B has initial velocity VoB= -30 m/sec and accelera ...continues