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, 
Answer:
Chemical changes are also known as chemical reactions. The “ingredients” of a reaction are called reactants, and the end results are called products.
Explanation:
Answer:
<em>The input power is 200 W</em>
Explanation:
<u>Motor Efficiency</u>
The efficiency of a motor can be calculated as follows:
Where:
β = efficiency
Po = Output power
Pi = Input power
Solving for Pi:
The efficiency is β=0.75 and the output power is Po=150 W, thus the input power is:
The input power is 200 W
Answer:
V₂ = 1.5 m/s
Explanation:
given,
speed of the first piece = 6 m/s
speed of the third piece = 3 m/s
speed of the second fragment = ?
mass ratios = 1 : 4 : 2
fragment break fly off = 120°
α = β = γ = 120°
sin α = sin β = sin γ = 0.866
using lammi's theorem
A,B and C is momentum of the fragments
4 x V₂ = 2 x 3
V₂ = 1.5 m/s
The Earth does revolves around the sun in a nearly circular orbit so the answer is T
