An object of mass m = 4.80 kg, attached to a spring scale, rests on a frictionle

Question

An object of mass m = 4.80 kg, attached to a spring scale, rests on a frictionless, horizontal surface as in the figure below. ( https://www.webassign.net/serpse8/6-p-020.gif) The spring scale, attached to the front end of a boxcar, reads zero when the car is at rest. (a) Determine the acceleration of the car if the spring scale has a constant reading of 17.9 N when the car is in motion. m/s2 to the right (b) What constant reading will the spring scale show if the car moves with constant velocity? N (c) Describe the forces on the object as observed by someone in the car. This answer has not been graded yet. (d) Describe the forces on the object as observed by someone at rest outside the car.

Explanation / Answer

a)

reading at spring scale = 17.9 N so force on object = 17.9 N

acceleration = F/m = 17.9/4.8 = 3.73 m/s^2 to the right

b)

car moves with constant velocity so acceleration is zero.

reading of spring scale = ma = 0 N

c)

if observer is in the car so acceleration of car and object will be same. so force on object for observer is zero.

d)

now observer is at the rest outside the car, if acceleration of car is 'a' then force on object F = ma

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.