Physics Answers

A crate at rest with a mass of 75 kg is being pushed by a force of 620 N. If the coefficient of kinetic friction between the crate and the floor is 0.55, determine how fast the crate will accelerate, and how far the crate will travel in 3.0 seconds.

An electron penetrates the region between two uniformly charged horizontal plates, but oppositely signed. Its initial speed, at half distance between the plates is 2×10 ^6 i m/s. The plates have a length of 4 cm and are 1.6 cm apart. In the whole region between the plates, the electric field ́ is uniform and perpendicular to the plates. (a) what is the maximum modulus that the vertical electric field can have so that the electron does not touch any plate?

The answer is 228 N/C but I'm not too sure how they got that?

The density of gold is 19.3 g/ cm3. What is this value in kilograms per cubic meter?

1. How long will a bus take to travel 150 km at an average speed of

40 km/h?

2.

2. A cheetah can run at 30 m/s, but only for about 12 s. How far

will it run in that time?

3. It takes a cheetah just 3 s to reach its top speed of 30 m/s.

What is its acceleration?

1. A pendulum has 15J of potential energy at the top of its swing.

a) What is its kinetic energy at the bottom of its swing?

You built a circuit consisting of three parallel plate capacitors with capacitances of 2.0 F, 3.0 F, and 5.0 F, respectively, which are connected in parallel. The whole circuit is connected to a 100 V line. What is the (a) total capacitance, (b) charge stored in each capacitor, and (c) potential difference across each capacitor?

An inclined plane as shown in figure 1 is used to raise an object of mass 30 kg. If the plane is

inclined 5° above the horizontal and the coefficient of friction is 0.20, calculate the ideal

mechanical advantage, actual mechanical advantage, and the efficiency of this machine.

If another galaxy is seen at a redshift of 0.5, what redshift would it see us at?

The series combination of five cells, each electromotive force of 1.5 V and internal resistance of 0.5Ω, is connected to an external resistance of 5.0 Ω. Find the (a) total internal resistance, (b) electromotive force of the battery, (c) total resistance of the circuit, (d) current through the external circuit, (e) terminal voltage of the battery, and (f) terminal voltage of a cell.

A galvanometer with a resistance of 15.0Ω gives a full-scale reading for current of 3.0 A. What shunt resistance is needed to convert this into an ammeter with a 30.0 A full-scale reading?