a 0.012kg rubber bullet travels at a velocity of 150m/s, hits a stationary 8.5kg concrete block resting on a frictionless surface, and ricochets in the opposite direction worth a velocity of -100m/s. how fast will the concrete block be moving?
This can be solve using momentum balance
Momentum = mv
Where m is the mass of the object
V is the velocity of the object
(0.012 kg) ( 150 m/s) + ( 8.5 kg) ( 0 m/s) = ( 0.012 kg) (
-100 m/s) + (v) ( 8.5 kg)
V = 0.35 m/s
Answer: The velocity of concrete block is 0.353 m/s
Explanation:
To calculate the velocity of the concrete block after the collision, we use the equation of law of conservation of momentum, which is:
\(m_1u_1+m_2u_2=m_1v_1+m_2v_2\)
where,
\(m_1\) = mass of rubber bullet = 0.012 kg
\(u_1\) = Initial velocity of rubber bullet = 150 m/s
\(v_1\) = Final velocity of rubber bullet = -100 m/s
\(m_2\) = mass of concrete block = 8.5 kg
\(u_2\) = Initial velocity of concrete block = 0 m/s
\(v_2\) = Final velocity of concrete block = ?
Putting values in above equation, we get:
\((0.012\times 150)+(8.5\times 0)=(0.012\times (-100))+(8.5\times v_2)\\\\v_2=\frac{1.8+1.2}{8.5}=0.353m/s\)
Hence, the velocity of concrete block is 0.353 m/s