Answer:
94 kg or 921.6 N
Explanation:
The velocity function is . The acceleration function, a(t), is the time derivative of the velocity function.
At ,
Because the elevator is going upwards, the net acceleration, where g us acceleration of gravity.
The resultant weight is
Since the bathroom scale is graduated in kg, it's reading is
Answer:
(a) F = 239.575 N (b) t = 0.00649s or 6.49 ms
Explanation:
(a) By law of energy conservation, the bullet kinetic energy will be transferred to work done on stopping it from moving.
Formula for Kinetic Energy where m is bullet mass, v is the velocity
Formula for work where F is the average force and S is the distance travelled.
Substitute m = 4.2 g = 0.0042 kg, v = 370 m/s and S = 1.2 (m)
(b) If the force is constant, since the mass is constant and F = ma according to Newton's 2nd law, the acceleration on bullet is also constant
We also have
At the time the bullet is coming to rest,
Therefore,