Answer:
<em>The stopping distance if the car skids is 225 ft</em>
Explanation:
<u>Friction</u>
It's a force that opposes movement and requires the interaction of two surfaces. If the interaction occurs from relative rest, then the friction force is greater than the case where the interactions occur from relative speed. The static coefficient is greater than the kinetic friction, and the relation is
If the car needs 180 ft to stop with slipping impending (no relative speed between the tires and the road), we can find the distance needed to stop the car in skidding conditions, which we expect to be greater.
This indicates that the friction forces have the same relation
Since the mass is the same:
Simplifying
Now we'll focus on the dynamic formulas. The acceleration can be computed from the initial speed vo, the final speed vf and the distance x:
This relation stands for both accelerations, which happen to be decelerations:
Where xk and xs are the distances needed to stop the car in each case. Note that vf and vo are the same since the test is done with the same values for both. Knowing the relation between the accelerations, we can have the relationship between the distances
Simplifying
Thus
Answer:
The heat rejected is 146J.
The work done by the engine is 54J.
The thermal efficiency is 0.27
Explanation:
The efficiency of the carnot engine, which is working between a hot source at a temperature and a cold source at a temperature , is given by:
The normal boiling point of water is 373 K. ()
The temperature of triple point of water is 273.15 K ()
Answer:
The height of the cliff is 121.276 m
Explanation:
Given;
initial velocity of the projectile, v₁ = 75 m/s
final velocity of the projectile, v₂ = 90 m/s
spring compression = 5 m
Apply the law of conservation of energy;
mgh₀ + ¹/₂mv₁² = mgh₂ + ¹/₂mv₂²
gh₀ + ¹/₂v₁² = gh₂ + ¹/₂v²
gh₁ - gh₂ = ¹/₂v₂² - ¹/₂v₁²
g(h₀ - h₂) = ¹/₂ (v₂² - v₁²)
h₀ - h₂ = ¹/₂g (v₂² - v₁²)
h₀ = h(cliff) + 5m
when the projectile hits the ground, Final height, h₂ = 0
Therefore, the height of the cliff is 121.276 m
Answer:
2.5A , 22500 JOULE
Explanation:
Resistance (R)= 6 ohm
Voltage (V) = 15 volt
a)
Current (I) = ?
From ohm's law,
V=IR
15 = 6*I
I = 2.5 A
b)
time(t) = 10min = 600 second
heat energy (Q) = ?
from Joule's law of heating,
Q = I²*R*t
Q = 2.5² *6*600
Q = 22500 Joule
hence, heat energy produced is 22500 joule.
Answer:
tA=tB
tB=(sA-dA)/vA watch it below
Explanation:
the spatio for A is sA=vA*tA+dA
the spatio for B is sB=vB*tB
the meeting point will happen at: tA=tB
so, sA=vA*tB+dA
tB=sB/vB
yields:
sA=vA*(sB/vB)+dA
sA-dA=vA*(sB/vB)
sB=(sA-dA)*vB/vA
then
tB=((sA-dA)*vB/vA)/vB
tB=(sA-dA)/vA