Question

A pile driver lifts a 350 kg weight and then lets it fall onto the end of a steel pipe that needs to be driven into the ground. A fall of 1.5 m before striking the pipe drives the pipe in 40 cm. What is the average force exerted on the pipe?

Answer 1

Answer:

force exerted will be 12862.5 N

Explanation:

We have given a fall of 1.5 m before striking the pipe

So h = 1.5 m

Mass m = 350 kg

Acceleration due to gravity $g=9.8m/sec^2$

So initial velocity $u=\sqrt{2gh}=\sqrt{2\times 9.8\times 1.5}=5.42m/sec$

Final velocity will be 0 m/sec

So v = 0 m/sec

Distance s = 40 cm = 0.4 m

From third equation of motion $v^2=u^2+2as$

So $0^2=5.42^2+2\times a\times 0.40$

$a=-36.75m/sec^2$

So force exerted will be equal to

$F=ma=350\times 36.75=12862.5N$

So force exerted will be 12862.5 N