Physics 1st Paper CQ-Chittagong Board-2022

1. A large vehicle of mass $1800 \mathrm{~kg}$ is moving at a speed of $72 \mathrm{kmh}^{-1}$ hit a small vehicle of mass $1000 \mathrm{~kg}$ parked in front from behind. After the collision, two vehicles moved together and stopped after $60 \mathrm{~m}$. Mahi who was standing on the side of the road as a student of science, observed the accident and said that it an inelastic collision.

2. On a certain day the temperature of upper surface of water of Kaptai lake is $28^{\circ} \mathrm{C}$. The atmospheric pressure and dew point are $10^{5} \mathrm{pa}$ and $10.5^{\circ} \mathrm{C}$ respectively. The temperature of bottom of the lake and the average density of water are $7^{\circ} \mathrm{C}$ and $1000 \mathrm{kgm}^{-3}$ respectively. The radius of and air bubble becomes three times when it comes from the bottom to the surface of the lake at that day. [The saturated vapour pressures at $10^{\circ} \mathrm{C}, 11{ }^{\circ} \mathrm{C}$ and $28^{\circ} \mathrm{C}$ are respectively $9.2,9.9$ and $28.5 \mathrm{~mm}$ $\mathrm{Hg}]$

3. A car of $1800 \mathrm{~kg}$ takes $30 \mathrm{sec}$ to reach the point $B$ from the point $A$ using the maximum power of engine along the inclined plane of the below figure with the driver of mass 60 $\mathrm{kg} \cdot\left[\mathrm{g}=9.8 \mathrm{~ms}^{-2}\right]$

4. A current of velocity $6 \mathrm{kmh}^{-1}$ is flowing in a river of 500 $\mathrm{m}$ width. Mahi and Nidhi decided to swim across the river to complete in the competition. Mahi started swimming at the angle of $\alpha$ with current with velocity $10 \mathrm{kmh}^{-1}$ and Nidhi started swimming vertically with the current with velocity 9 $\mathrm{kmh}^{-1}$.

5. An artificial satellite was placed at $26000 \mathrm{~km}$ above from the earth's surface of Dhaka. Radius of the earth is $6400 \mathrm{~km}$ and mass is $6 \times 10^{24} \mathrm{~kg}$.