Physics Answers

A rock is thrown horizontally from the top of a cliff 88 m high, with a horizontal speed

of 25 m/s.With what velocity does the rock hit?

An automobile is pushed 120 inches by a woman exerting 80 lbs of force horizontally on the vehicle. How much work does she do (a) in ft ⋅ lb and (b) in joules?

A box is pulled across a level floor a distance of 0.1 km. Given that 2.0 kJ of work was done in overcoming friction, what was the average friction force?

A force of 3.0 N acts through a distance of 12m in the direction of the force. Find the work done.

How much work is needed to move a proton from a point with an potential of +75 V to a point where it is -25 V?

If the work required to speed a car from 10 km/h to 20 km/h is 5.0 x 103 J, what would be the work required to increase its speed from 20 km/h to 30 km/h.

In an experiment one finds that a force of 160 N produces a stretch of 8.00 cm in a

given spring. What is the spring constant of the spring?  

. If the stress produced in stretching a wire is 5.00 x 10 6 N/m2 by an applied force of

10.0 N, what is the cross-sectional area of the wire?  

At 0.0°C and 1.00 atm, 1.00 mol of a gas occupies a volume of 0.0224 m³.

If the gas is nitrogen (N₂), the principal component of air, what is the mass density? Molar mass of Nitrogen is 14.00674 g/mol.

At 0.0°C and 1.00 atm, 1.00 mol of a gas occupies a volume of 0.0224 m³.

 What is the number density?