Answer:
u = 449 m/s
Explanation:
Given,
Mass of the bullet, m = 26 g
Mass of the wooden block,M = 4.7 Kg
height of the block,h = 0.31 m
initial speed of the block, u = ?
Using conservation of energy




v = 2.47 m/s
Now, using conservation of momentum to calculate the speed of the bullet.
m u + M u' = (M+m)v
m u = (M+m)v
0.026 x u = (4.7+0.026) x 2.47
u = 449 m/s
Hence, the speed of the bullet is equal to 449 m/s.
Answer: An object at rest has zero velocity - and (in the absence of an unbalanced force) will remain with a zero velocity. Such an object will not change its state of motion.
Explanation: I hoped that helped!!
The spring has been stretched 0.701 m
Explanation:
The elastic potential energy of a spring is the potential energy stored in the spring due to its compression/stretching. It is calculated as

where
k is the spring constant
x is the elongation of the spring with respect to its equilibrium position
For the spring in this problem, we have:
E = 84.08 J (potential energy)
k = 342.25 N/m (spring constant)
Therefore, its elongation is:

Learn more about potential energy:
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If you put 300 J of heat into an engine with an efficiency of 0.35, how much work can be done? 3. How much energy must be put into an engine with an efficiency of 0.6 if 270 J of work are required? 4. An engine with an efficiency of 0.425 uses 1200 J of energy. Find the amount of energy wasted by the engine. 5. Calculate the efficiency of an engine operating between temperatures of 258 K and 600 K 6. An engine runs with its exhaust (cold) reservoir at a temperature of 200 K. To what temperature should the input (hot) temperature be set if an efficiency of 0.8 is desired? 7. Complete the following table of temperatures. Fahrenheit Celsius Kelvin 213 15 98.6 75 408