Question

1. a 373 kg boulder is pulled with a rope across a field by a strong man. if the man uses a force of 1802 n to cause the boulder to accelerate across the field. if the coefficient of friction is 0.38, how fast does the strong man accelerate the boulder?

Explanation:

Step1: Calculate the normal force

The normal force \(N\) on the boulder is equal to its weight since there is no vertical acceleration. Using \(N = mg\), where \(m = 373\ kg\) and \(g=9.8\ m/s^{2}\).

$$N=373\times9.8 = 3655.4\ N$$

Step2: Calculate the frictional force

The frictional force \(f=\mu N\), with \(\mu = 0.38\) and \(N = 3655.4\ N\)

$$f=0.38\times3655.4=1389.052\ N$$

Step3: Apply Newton's second law

Newton's second law is \(F_{net}=ma\), and \(F_{net}=F - f\), where \(F = 1802\ N\), \(f = 1389.052\ N\) and \(m = 373\ kg\)

$$a=\frac{F - f}{m}=\frac{1802- 1389.052}{373}$$

$$a=\frac{412.948}{373}\approx1.02\ m/s^{2}$$

Answer:

$1.02\ m/s^{2}$