Other Physics Answers

A uniform bar of weight 40 N is 4 m long. Weights of 60N and 100N are placed on the bar at points which are 1.5m and 3m, respectively, from the left end. At what point on the bar must a single force be applied to support it in a horizontal position? 

A non-uniform bar 2 meters long is supported by means of a string tied at its midpoint. To keep the bar in a horizontal position, a downward force of 60 Newton must be applied at the thinner end of the bar. If the weight of the bar is 120 Newton, Locate its center of gravity. 

A uniform bar weighing 60 N has a length of 4 m and is supported at its end by strings. A load W=200N is placed at some point on the bar such that it is in equilibrium when the tension in the string at the left end is 80N. (a) Locate the position of W, (b) find the tension in the string at the right end

A small box (1.6 kg) is kicked down an incline with an initial speed of 6.8 m/s. The incline makes an angle of 17.9o relative to horizontal and the force of friction has 30% of the magnitude of the normal force. What is the acceleration of the box? Use a forces approach to solve

An elevator is travelling 2.50 m/s upward when the brakes are put on. The acceleration is 𝑎⃑ = 1.25 𝑚 𝑠 2 downward while the brakes are applied. Using kinematics: a) How many seconds does it take to bring the elevator to a stop? b) Calculate the displacement vector of the elevator while it is being brought to a stop. 

A large object slides down a frictionless slope that is inclined at 15o . It has an initial speed of 4 m/s. What is the speed of the object after it has slid 7 m along the slope? Solve using an energy approach. 

Damon pulls on a large block (40 kg) with a force 𝐹⃑ = 13𝑁 𝑖̂+ 3𝑁 𝑗. Maggie ̂ pushes the block with a 12N 𝑖̂force. The block is initially moving to the right. The friction force has a magnitude of 26 N. Using a forces approach, find the acceleration of the block and state if the block is speeding up or slowing down.

A child drops a brick from their balcony. It hits the ground 8 s after it is dropped. Using kinematics: (a) When the brick hits the ground, what is the displacement of the brick from the point where it was dropped? (b) What is the velocity of the brick just before it hits the ground?

A conducting loop is held below a current carrying wire PQ as shown. Predict the direction of the

induced current in the loop when the current in the wire is constantly increasing.

In a Compton scattering, the incident Cu-Kα photon has a wavelength of 1.54 Å. The ratio of the maximum kinetic energy of the recoiled electron to the energy of the incident photon will be

A solid, uniform cylinder with mass M and radius R is spinning with an angular velocity W on a thin, frictionless axle that passes along the cylinder axis. You design a simple friction brake to stop the cylinder by pressing the brake against the outer rim with a normal force. The coefficient of kinetic friction between the brake and rim is µ. Find the applied normal force to bring the cylinder to rest after it has turned through N revolution?

Two strings support a small 8-kg body. Find the tension in the strings if they both make 

30o with the vertical.