Answer:
v = 24 m/s, rightwards
Explanation:
Given that,
The mass of TBT explosive = 5 kg
It explodes into two pieces.
One of the pieces weighing 2.0 kg flies off to the left at 36 m/s. Let left be negative and right be positive.
The law of conservation of momentum holds here. Let v be the final speed of the remaining piece. So,

So, the final speed of the remaining piece is 24 m/s and it is in the right direction.
Acceleration = (change in speed) / (time for the change)
Change in speed = (later speed) - (earlier speed) = (13 - 24) = -11 km/hr
Time for the change = 2 seconds
Acceleration = (-11 km/hr) / (2 sec)
Acceleration = -5.5 km/hr-sec (B)
Answer:
The rate of the boat in still water is 44 mph and the rate of the current is 4 mph
Explanation:
x = the rate of the boat in still water
y = the rate of the current.
Distance travelled = 120 mi
Time taken upstream = 3 hr
Time taken downstream = 2.5 hr
Speed = Distance / Time
Speed upstream

Speed downstream

Adding both the equations


The rate of the boat in still water is <u>44 mph</u> and the rate of the current is <u>4 mph</u>
Answer:
The velocity of the truck after this elastic collision is 15.7 m/s
Explanation:
It is given that,
Mass of the car, 
Mass of the truck, 
Initial velocity of the car,
Initial velocity of the truck, u₂ = 0
After the collision the velocity of the car is, v₁ = -11 m/s
Let v₂ is the velocity of the truck after this elastic collision. Using the conservation of momentum as :

So, the velocity of the truck after this elastic collision is 15.7 m/s. Hence, the correct option is (c).