Question

Two large crates, with masses 640kg and 490kg , are connected by a stiff, massless spring (K=8.1kN/m) and propelled along an essentially frictionless, level factory floor by a force applied horizontally to the more massive crate. If the spring compresses 5.1 from its equilibrium length, what is the applied force? Express your answer using two significant figures. The answer is suppose to be 950N

Answer 1

950.7 N

Step-by-step explanation:

m1 = 640kg

m2 = 490kg

k = 8.1 kN/m

the spring is compressed by 5.1cm

5.1/100 = 0.051m

F = kx

F = 8100 * 0.051

F = 413.1 N

F is the force of the small crate.

F(small) = ma

431.1 = 490a

a = 431.1/490

a = 0.84 m/s^2

The acceleration for the smaller crate is the same for the large create.

F(large) = ma

= 640 * 0.84

= 537.6N

Total force = F(small) + F(large)

= 413.1 + 537.6

= 950.7N