Answer:
D
Explanation:
By law of conservation of momentum:
momentum before collision = momentum after collision
Initial speed of bullet is unknown whereas initial speed of pendulum will be zero as it was at rest.
Final speed of bullet and pendulum will be equal as bullet is embedded in pendulum and both moves together a vertical distance of 6.89cm.
Using third equation of motion:
where:
Thus by placing values 
this speed will be final speed of collision for the calculation of initial speed of bullet.
Putting values:
This 224m/s = 0.224Km/s which is closest to D
Answer:
<h3>4905N</h3>
Explanation:
The force needed to keep the elephant from slowing down is expressed as shown according to Newtons second law of motion.
Force = mass * acceleration due to gravity
Given
Mass of elephant = 500kg
acceleration due to gravity = 9.81m/s²
Force = 500*9.81
Force = 4905N
<em>Hence the force needed to keep the elephant from slowing down is 4905N</em>
Answer:
16 mm with 14 mm inside diameter.
Vector trigonometry can be used for this problem. Since the horizontal component is 12 meters per second, this is technically the hypotenuse (actual initial velocity) multiplied to cosine of 40 degrees. Therefore, to find the hypotenuse, we must divide 12 by cosine 40degrees. cos(40)= 0.766, and 12/0.766 = approximately 15.664, therefore our answer is (3) 15.7 m/s
