Physics Answers

When you load a heavy box into a big moving truck, it is often easier to push it up a sloped frictionless ramp to the back of the truck than to lift it directly up into the truck. Yet, the change in the gravitational potential energy of the box is the same no matter how you get it from the ground into the moving truck.

Compare the amount of work you must do to lift the box directly into the truck with the amount of work you need to push the box up the frictionless ramp.

A typical capacitor in a memory cell have a capacitance of 3 x 10-14 F. If the voltage across the capacitor is 0.5 V, what is the number of electrons that must move to the capacitor to charge it? 

A stone projected horizontally from the top of a tower with a speed of 5m/s. It lands on the ground level of the horizontal distance of 20m from the top of the tower. Calculate the height of the tower. g= 10m/s²

A car is traveling at a speed of 33 m/s. (a) What is its speed in kilometers per hour? (b) Is it exceeding the 90 km/h speed limit?

A beach ball is rolling in a straight line toward you at a speed of 0.5 m/s. Its momentum is 0.25 kg*m/s.

What is the mass of the beach ball?

Two point charges are placed as follows: charge q1 = -1.50 nC is at y = +6.00 m and charge q2 = +3.20 nC is at the origin. What is the total force (magnitude and direction) exerted by these two charges on a negative point charge q3 = -5.00 nC located at (2.00 m, -4.00 m)? 

A gardener pushes a lawnmower of mass 18kg at a constant speed. To do this requires a force P of 80N directed along the handle, which is at an angle of 40°to the horizontal.

a) Calculate the horizontal frictional force

b) If this frictional force were constant, what force, applied along the handle, would accelerate the mower from rest to 1.2m/s in 2.0s?

the erth is on average 150 million kilometers from the sun calculate it's average speed in orbit?

4. A constant force of 45N acts on a 15 kg box. The direction of the force is to the left. If the box is originally at rest, what will be its velocity after 5s? Indicate the magnitude and direction of the velocity.

Three indistinguishable particles are to be distributed in two cells. Find possible number of

macrostates and corresponding number of microstates.