um the answer is A
np :3 i hope this is right
Answer:
We feel cold when tap or well water in winter because heat flows from hot body to cold body.
Explanation:
Our <em>body</em><em> </em><em>is</em><em> </em><em>in</em><em> </em><em>optimal</em><em> </em><em>status</em><em> </em><em>is</em><em> </em><em>a</em><em> </em><em>hot</em><em> </em><em>body</em><em> </em><em>and</em><em> </em><em>tap</em><em> </em><em>or</em><em> </em><em>we</em><em>ll</em><em> </em><em>water</em><em> </em><em>is</em><em> </em><em>a</em><em> </em><em>cold</em><em> </em><em>body</em><em>.</em><em> </em><em>Theref</em><em>ore</em><em> </em><em>we</em><em> </em><em>feel</em><em> </em><em>cold</em><em>.</em>
Answer:
right away because you should never speed
Answer:
1-An object's velocity will change if a net force acts on the object. (True)
2-In order not to slow down, a car moving at a constant velocity needs a small net force applied. (False)
3- The net force which acts on an object which remains at rest is zero. (True)
4- If an object's speed does not change, no net force is acting on the object.(True)
5- If two objects are under the influence of equal forces, they have the same acceleration. (False)
6- During the collision of a car with a large truck, the truck exerts a greater force on the car than the car exerts on the truck.(False) (Newton Third Law)
Answer:
α = -0.01625 rad / s²
Explanation:
This is an exercise in angular kinematics, we can use the relation
w = w₀ + 2 α θ
linear and angular variables are related
v = w r
w = v / r
Let's reduce the magnitudes to the SI system
v₀ = 91 km / h (1000m / 1km) (1h / 3600s) = 25.278 m / s
v = 48 km / h = 13,333 m / s
θ = 75 rev (2π rad / 1 rev) = 471.24 rad
Let's find the angular velocities
w₀ = v₀ / r
w₀ = 25.278 / 0.78
w₀ = 32,408 rad / s
w = v / r
w = 13.333 / 0.78
w = 17.09 rad / s
we calculate the angular acceleration
α = (w- w₀) / 2θ
α = (17.09 - 32.408) / (2 471.24)
α = -0.01625 rad / s²
the negative sign indicates that the wheel is stopping