Question

The momentum of a falling rock is found to be 200 kg m/s. What is the mass of the rock if it falls with a velocity of 5.0 m/s

Answer 1

Answer:

$\boxed {\boxed {\sf 40 \ kilograms}}$

Explanation:

Momentum is the product of velocity and mass. The formula is:

$p=m*v$

We know the rock is falling. Its momentum is 200 kilograms meters per second and its velocity is 5 meters per second. Substitute the values into the formula.

$200 \ kg \ m/s = m * 5.0 \ m/s$

We are solving for m, the mass. We must isolate the variable. It is being multiplied by 5 meters per second. The inverse of multiplication is division, so we divided both sides by 5.0 m/s.

$\frac{200 \ kg \ m/s}{5.0 \ m/s}=\frac{ m* 5.0 \ m/s }{5.0 \ m/s}$

$\frac{200 \ kg \ m/s}{5.0 \ m/s}=m$

The units of meters per second (m/s) cancel.

$\frac{200 \ kg}{5.0 } =m$

$40 \ kg = m$

The falling rock has a mass of 40 kilograms.