The person walking down the sidewalk follows the newton's third law of motion.
Explanation:
- A person is able to walk down the sidewalk by using the reaction forces from the ground.
- In simple term, feet pushes the ground and the reaction forces makes the feet able to walk.
- Another important force included in the walking mechanism is friction. With out friction one cannot walk down the sidewalks.
- Hence the forces involved in the walking of a person down the sidewalk are:
- Friction force
- Action and reaction force between ground and person's feet.
The weight of the cooler is (mg). That's (26)(9.8) = 254.8 Newtons.
Its gravitational potential energy while it's up in the top row is (mgh). That's (254.8)(17.5) = 4,459 Joules.
That's how much work it took to get the cooler up to the top row, and that's the energy it gives up when it moves back down to the bench.
In order to bring it down . . .
-- Gravity does 4,459 joules of work on the cooler.
-- The team assistant does NEGATIVE 4,459 joules of work on it.
I = Delta p
I = Impulse
Delta p = Momentum variation
Delta p = pf - po
Pf = Final momentum
Po = Initial momentum
p = m x v
M = Mass
V = Velocity
Delta p = (m x Vf) - (m x Vo)
I = 1.2 x 10^3 x 20 - 12 x 10^2 x 18
I = 2.4 x 10^4 - 216 x 10^2
I = 2.4 x 10^4 - 2.16 x 10^4
I = 0.24 x 10^4
I = 24 x 10^2 Newtons x seconds (N x s)
Answer: The value of impulse is 24 x 10^2 Newtons x seconds (N x s).
Answer:
-4.4 m/s
Explanation:
Since the ball is thrown upward, we can ignore the horizontal velocity. This means that the vertical velocity is 25 m/s. The vertical acceleration is -9.8 m/s^2 (g). This means that after 3 seconds, the velocity would've decreased by 9.8 m/s^2 * 3 s. This is 29.4 m/s.
This should be subtracted from the initial velocity:
25 m/s - 29.4 m/s = -4.4 m/s
Hope this helps!
Option C: Later in the day, less power is developed in lifting each box
