Answer:
The value of speed of wooden block at the instant after the collision
262.41 
Explanation:
Given data
Mass of block = 6.3 kg
Mass of bullet = 0.086 kg
Velocity of bullet
= 266 
Final velocity of whole system is

Put all the values in above formula we get

262.41 
This is the value of speed of wooden block at the instant after the collision.
Answer:
Distance, d = 99990 meters
Explanation:
It is given that,
Speed of the train, v = 200 km/h = 55.55 m/s
Time taken, t = 1800 s
Let d is the distance covered by the train. We know that the speed of an object is given by total distance covered divided by total time taken. Mathematically, it is given by :



d = 99990 m
So, the distance covered by the train is 99990 meters. Hence, this is the required solution.
Conveniently, some scientists have already figured out how much heat energy it takes to increase the temperature of one gram of water by exactly 1 degree Celsius. That is called the specific heat of water and it's value is 4.184J/g.
So simply multiply the specific heat with the number of grams and the number of degrees C like this:
Answer:
A) 8π ft²/ft
B) 24π ft²/ft
C) 48π ft²/ft
Explanation:
Surface area of the spherical balloon is not clear here but it is supposed to be;
S = 4πr²
where:
r is the radius of the spherical balloon
So thus, the rate of change of the surface area of the spherical balloon by its radius will be:
dS/dr = 8πr
A) at r = 1ft;
dS/dr = 8 × π × 1
dS/dr = 8π ft²/ft
B) at r = 3 ft;
dS/dr = 8 × π × 3
dS/dr = 24π ft²/ft
C) at r = 6ft;
dS/dr = 8 × π × 6
dS/dr = 48π ft²/ft