Answer:

Explanation:
As per the formula of thermal expansion we know that

so here we will have



so here change in the length of the rod is given as




Clock wise idk i think you should double check my answer
Answer:
0.34 m/s^2
Explanation:
force=mass × acceleration
400 =1200 × acceleration
acceleration=400/1200
=0.34 m/s^2
Answer
given,
before collision
mass of car A = m_a = 1300 kg
velocity of car A = v_a = 35 mph
mass of car B = m_b= 1000 kg
velocity of car B = v_b = 25 mph
after collision
V_a = 30 mph
V_b = 31.5 mph
Initial momentum



final momentum



here initial momentum is equal to the final momentum of the car.
hence, momentum is conserved in the collision.
Answer:
Explanation:
1. We use the conservation of momentum for before the raining and after. And also we take into account that in 0.5h the accumulated water is
100kg/h*0.5h = 50kg

2. the momentum does not conserve because the drag force of water makes that the boat loses velocity
3. If we assume that the force of the boat before the raining is

where we have assumed that the acceleration of the boat is 1m/s{2} just before the rain starts
And if we take the net force as

where we take v=1m/s because we are taking into account tha velocity just after the rain stars.
I hope this is useful for you
regards