Question

An object of mass 100gm drops from rest 490cm downward. Traversing 70cm inside sand it stops. Calculate the acceleration posed by the sand on the object?

Answer 1

Answer:

Acceleration = - 68.6m/s^2

Explanation:

We will be using equation of motion to solve this question;

Using the equation;

v^2-u^2=2as

where u is the initial velocity, v final velocity, a acceleration and s is distance covered.

In this case;

u=0,v=?   s=490cm=4.9m., a= g= 10

v^2-u^2=2as

v^2 = 2 x 10 x 4.9

from this we get v=9.8

Now take it as u in the second case .then v=0 s=70cm=0.7m

again use the third kinematic equation.

v^2-u^2=2as

0 – 9.89^2= 2 a (0.7)

- 96.4 = 1.4 x a;

then we get answer a=-68.6m/s^2