Physics Answers

In the figure below, a spring with k = 170 N/m is at the top of a frictionless incline of angle θ = 370. The lower end of the incline is distance D = 1.00 m from the end of the spring, which is at its relaxed length. A 2.00 kg canister is pushed against the spring until the spring is compressed 0.200 m and released from rest. (a) What is the speed of the canister at the instant the spring returns to its relaxed length (which is when the canister loses contact with the spring)? (b) What is the speed of the canister when it reaches the lower end of the incline?

Leonard wanted to measure the depth of the dried-up well beside their house. He dropped a coin in to it, and it took 2 seconds for the coin to reach the ground. What is the total depth of the well? (Disregard the external factors that might affect the coin’s velocity.)

A wire made of copper is found to have a change in resistance of 17% after its temperature change. If the resistance of this wire was 8.66 Ω at 20 ⁰C, and the resistivity after the change in temperature is found to have decreased, determine the following: 

If the wire is connected to 14 V battery, how many electrons pass through a cross-sectional area A in 3 min after temperature change, assuming the wire is an ohmic conductor          

Select one:

 2.2×10²¹ electrons

1.6×10¹⁹ electrons 

3.6×10¹⁹ electrons

1.2×10²¹ electrons

a train moving away from a sound detector at 30.0 m/s blows a 300-hz whistle.speed of sound is 340 m/s.what frequency is detected on each of the following?

a.stationary train.

b.a train moving away from the first train at speed of 20.0 m/

A wheel rotatung at 1p.5rads-1 takes 5.2 to stop calculate

Angular acceleration

The number if revolution the wheel makes before it stops

If a 20-kg object experiences a 30-N force for a duration of 0.20-second, then what is the momentum

change of the object?

Two forces, F₁ = 8.0 N, 60^o Northwest and F₂ = 12.0 N, Southwest, are applied to a particle at the origin. What third force is needed so that the particle will not be displaced from the origin?

Air is contained in a vertical piston–cylinder assembly fitted with an electrical resistor. The atmosphere exerts a pressure of 1 bar on the top of the piston, which has a mass of 45 kg and a face area of .09 m2 . Electric current passes through the resistor, and the volume of the air slowly increases by .045 m3 while its pressure remains constant. The mass of the air is .27 kg, and its specific internal energy increases by 42 kJ/kg. The air and piston are at rest initially and finally. The piston–cylinder material is a ceramic composite and thus a good insulator. Friction between the piston and cylinder wall can be ignored, and the local acceleration of gravity is g=9.81 m/s2 . Determine the heat transfer from the resistor to the air, in kJ, for a system consisting of (a) the air alone, (b) the air and the piston

What is the velocity and direction of the collision if a rail way train with mass of 6000kg is moving to

the right at 2.0m/s and collides with an empty freight train mass 3,000kg which is moving to the left on

the same track at 3.0m/s?

Answer the following conceptual questions and practice about potential and kinetic energy.

1. You have two balls, a tennis ball and a baseball with twice the mass of the tennis ball. If you want to throw both balls with the same kinetic energy, how much faster should the tennis ball be compared to the baseball?