Answer:
The final velocity of the bullet is 9 m/s.
Explanation:
We have,
Mass of a bullet is, m = 0.05 kg
Mass of wooden block is, M = 5 kg
Initial speed of bullet, v = 909 m/s
The bullet embeds itself in the block which flies off its stand. Let V is the final velocity of the bullet. The this case, momentum of the system remains conserved. So,
So, the final velocity of the bullet is 9 m/s.
Density = Mass/Volume
So, given mass = 20 g and volume = 40 cm^3
By substituting in above equation, Density = 20/40 = 0.5 g/cm^3
Hope it helps.
Answer: 2 seconds is the unit rate.
Explanation:
We know that Jason does 30 pushups in 60 seconds at a constant rate, and we know that each push up takes 2 seconds.
then, we can write this as 30 pushups/60 seconds = (1/2) pushups per second.
Here, two seconds represents the time needed to do one pushup, is the unit rate (this means that we need 2 seconds to have a unit "one pushup")
