An 800 kg car moving at 80 km hr\(^{-1}\) collides with a 1200 kg car
PHYSICS
WAEC 2019
An 800 kg car moving at 80 km hr\(^{-1}\) collides with a 1200 kg car moving at 40 km hr\(^{-1}\) in the same direction. If the cars stick together, calculate their common velocity.
- A. 60 km hr\(^{-1}\)
- B. 8 km hr\(^{-1}\)
- c. 40 km hr\(^{-1}\)
- d. 56 km hr\(^{-1}\)
Correct Answer: B. 8 km hr\(^{-1}\)
Explanation
From momentum conservation
(800 x 80) - (1200 x 40)
= (800 + 1200) V
= 64000 - 48000 = 2000V
16000 = 2000V
V = \(\frac{16000}{2000}\)
= 8kmh\(^-1\)
The common velocity = 8kmhr\(^{-1}\)
Post an Explanation Or Report an Error
If you see any wrong question or answer, please leave a comment below and we'll take a look. If you doubt why the selected answer is correct or need additional more details? Please drop a comment or Contact us directly. Your email address will not be published. Required fields are marked *