Answer:
There are four forces acting on a bird in flight, lift, thrust, drag and gravity (weight). These four forces act in pairs, as shown on the right. If a bird is to fly it must overcome drag and weight by generating a greater force of thrust and lift.
Answer: 3217.79 hours.
Explanation:
Given, A 140 lb. climber saved her potential energy as she descended from Mt. Everest (Elev. 29,029 ft) to Kathmandu (Elev. 4,600 ft).
Power = 0.4 watt
Mass of climber = 140 lb
= 140 x 0.4535 kg [∵ 1 lb= 0.4535 kg]
⇒ Mass of climber (m) = 63.50 kg
Let
and 
Now, Energy saved =
![\text{Power}=\dfrac{\text{energy}}{\text{time}}\\\\\Rightarrow 0.4=\dfrac{4633620.91}{\text{time}}\\\\\Rightarrow\ \text{time}=\dfrac{4633620.91}{0.4}\approx11584052.28\text{ seconds}\\\\=\dfrac{11584052.28}{3600}\text{ hours}\ \ \ [\text{1 hour = 3600 seconds}]\\\\=3217.79\text{ hours}](https://tex.z-dn.net/?f=%5Ctext%7BPower%7D%3D%5Cdfrac%7B%5Ctext%7Benergy%7D%7D%7B%5Ctext%7Btime%7D%7D%5C%5C%5C%5C%5CRightarrow%200.4%3D%5Cdfrac%7B4633620.91%7D%7B%5Ctext%7Btime%7D%7D%5C%5C%5C%5C%5CRightarrow%5C%20%5Ctext%7Btime%7D%3D%5Cdfrac%7B4633620.91%7D%7B0.4%7D%5Capprox11584052.28%5Ctext%7B%20seconds%7D%5C%5C%5C%5C%3D%5Cdfrac%7B11584052.28%7D%7B3600%7D%5Ctext%7B%20hours%7D%5C%20%5C%20%5C%20%5B%5Ctext%7B1%20hour%20%3D%203600%20seconds%7D%5D%5C%5C%5C%5C%3D3217.79%5Ctext%7B%20hours%7D)
Hence, she can power her 0.4 watt flashlight for 3217.79 hours.
Answer:
The speed of the 8-ball is 2.125 m/s after the collision.
Explanation:
<u>Law Of Conservation Of Linear Momentum</u>
The total momentum of a system of masses is conserved unless an external force is applied. The momentum of a body with mass m and velocity v is calculated as follows:
P=mv
If we have a system of masses, then the total momentum is the sum of all the individual momentums:

When a collision occurs, the velocities change to v' and the final momentum is:

In a system of two masses, the law of conservation of linear momentum is simplified to:

The m1=0.16 Kg 8-ball is initially at rest v1=0. It is hit by an m2=0.17 Kg cue ball that was moving at v2=2 m/s.
After the collision, the cue ball comes to rest v2'=0. It's required to find the final speed v1' after the collision.
The above equation is solved for v1':




The speed of the 8-ball is 2.125 m/s after the collision.
Answer:
The answer is below
Explanation:
Momentum is used to measure the quantity of motion in an object. Momentum is the product of mass and velocity.
Momentum = mass * velocity
The principle of conservation of momentum states that momentum cannot be created or destroyed but can be transferred. Therefore the momentum before and after an action is equal.
Initial momentum = Final momentum
Let m be the mass of the diver, M be the mass of the raft, u be the initial velocity of the diver, U be the initial velocity of the raft, v be the final velocity of the diver and V be the final velocity of the raft.
m = 71 kg, M = 500 kg, v = 6 m/s
Initial both the raft and diver are at rest, hence u and U is zero, hence:
mu + MU = mv + MV
71(0) + 500(0) = 71(6) + 500(V)
0 = 426 + 500(V)
500(V) = -426
V = -426/500
V = -0.852 m/s
Making a drawing of the system, we will have two forces which are tension and the weight of the object. Balancing the forces present, we do as follows:
T = W
W = 30 N
Therefore, weight is equal to 30 N. Hope this answers the question. Have a nice day. Feel free to ask more questions.