Mechanics | Relativity Answers

an object weight 712.0 N is is being pushed along a horizontaL surface by a 440.0 N force. what is the mass of the object? how would you find that? what is newton force? how do you use it in this situation? is it really needed to find the mass of the object?

An object is placed 4 cm in front of a concave lens of focal length 3 cm. Using the lens equation, find where the image will form and state whether it is a real or virtual image.

How much heat must a refrigerator remove from 100 g of water at 25 º C to convert it to ice at 0º C? (Specific heat of water = 1 cal /gº C and heat of fusion of ice = 80 cal/g at 0º C)

What is the frequency of a sound wave in air at 20°C that has a wavelength of 0.4 m?

A cubical object of sides 5 cm is immersed completely in water. What is the force of buoyancy on the object? (Assume g = 10 m/s2)

A helicopter is ascending at rate of 12 m/s . At a height of 80 m above the ground ,a package is dropped .how long does the package take to reach the ground ?

an object falls freely from rest for 5 seconds. Find the distance travelled in the last 2 seconds. (g=9.8m/s square)

Two people (one with a mass of 40 kg and the other having a mass of 60kg) stand at one end of a small uniform boat of mass 100 kg and length 20 m. The 60kg person now slowly walks to the other end of the boat. Determine how far the boat moves in the process assuming no friction between the boat and water.

two cars travelling towards each other on a straight road at velocity 10 m/s and 12 m/s respectively.when they are 150 m apart,drivers apply their brakes and each can decelerate at 2 m/s until it stops.how far apart will they be when they have both come to stop?

A police car is moving at 29 m/sand is behind a speeding car moving faster in the same direction as the police car. The radar gun in the police car emits an 8.0x109 Hz electromagnetic wave. The frequency of the returning wave is measured to be 318Hz less than the emitted frequency. Find the speeder's speed.