Physics Answers

Water from a dam falls on a turbine 30 m below at the rate of 60 m³/min. After

leaving the turbine wheel the water has a velocity of 9 m/s. What is the maximum

efficiency of the turbine? What is the maximum power developed?

.A crane lifts a 75kg mass a height of 8 m. Calculate the gravitational potential energy gained by the mass (g = 9.8 N/kg).

A 0.65 kg body when attached to a spring of force constant 225N/m oscillates with a maximum speed of 0.15 m/s. Find its amplitude and acceleration of the mass when it passes its equilibrium position.

Two systems are transitioned from State A to State B through different processes. Process 1 takes the system from state A to state B at a higher pressure than process 2.

How does the change in internal energy compare for both processes

A)  process 1 has a smaller change in internal energy 

B) both processes have the same change in internal energy

C) not enough given to decide 

D) process 1 has a bigger change in internal energy 

Calculate the final equilibrium temperature when 150 grams of 23 degrees Celsius water are mixed with 50 grams of ice at 0 degrees Celsius. The specific heat of water is 4186J/Kg C and the heat of fusion for water is 334 Kj/kg

the propagation speed of sound wave (standing waves in a stopped pipe). Using the apparatus you used for Lab11, you strike

a tuning fork and find that the first harmonic/fundamental resonance is produced when the air column length or height or depth

at 0.166 m. If the speed of sound is 340 m/s, what is the frequency of sound wave produced by the tuning fork in Hz?

A uniform rod rotates in a horizontal plane about a vertical axis through a point

which is 2 m away from its center. The rod is 8 m long, weighs 8 N, and rotates at 100

rev/minute. Calculate

(a) Its rotational inertia about the axis of rotation.

(b) The magnitude of its angular momentum about the axis.

A uniform 2.5 kg disk of radius 30 cm is rotating around its central axis at an

angular speed of 72 rad/s. At time t=0, a man begins to slow it at a uniform rate until it stops

at t = 8 s.

(a) By time t = 5 s, how much work had the man done?

(b) For full 8 s, at what average rate did the man do work?

A 5.5 g bullet moving at 120 m/s strikes a thick wall. Assume that the bullet

undergoes a uniform deceleration and stops after penetrating 6 cm within the wall. Find

(a) The time taken by the bullet to stop.

(b) The impulse on the wall.

(c) The magnitude of the average force experienced by the wall

A 4.0 kg bundle starts up a 30° incline with 200 J of kinetic energy. How far will it

slide up the incline if the coefficient of kinetic friction between the bundle and the incline is

0.42?