Answer:
distance changing at rate of 3.94 inches/sec
Explanation:
Given data
wall decreasing at a rate = 9 inches per second
ladder L = 152 inches
distance h = 61 inches
to find out
how fast is the distance changing
solution
we know that
h² + b² = L² ..................1
h² + b² = 152²
Apply here derivative w.r.t. time
2h dh/dt + 2b db/dt = 0
h dh/dt + b db/dt = 0
db/dt = - h/b × dh/dt .............2
and
we know
h = 61
so h² + b² = L²
61² + b² = 152²
b² = 19383
so b = 139.223
and we know dh/dt = -9 inch/sec
so from equation 2
db/dt = -61/139.223 (-9)
so
db/dt = 3.94 inches/sec
distance changing at rate of 3.94 inches/sec
Answer:
<em>The engine must provide power to compensate friction</em>
Explanation:
<u>Accelerated Motion
</u>
Newton's first law states that a body will keep its speed or state of rest while no external net force is applied. Our automobile is running through a road which surface exerts a frictional force on the wheels. If we didn't use fuel, the automobile will eventually stop, because the unbalanced friction force causes deceleration. To compensate that force, we must provide power to the engine. When our speedometer shows a constant speed, the net force is zero, but the car needs to accelerate some, just to compensate the friction force.
The total acceleration keeps being zero, but the engine is actually doing work against friction.
Answer:
A
Explanation:
Pushing a car up a steep hill is the most work. First of all a car is heavy. Secondly, its hard to walk up a steep hill let alone push a car up one.
Answer:
D
Explanation:
Jack nd Jill did the same amount of work but jack had more power
Please give brainlist
Answer:
t = 0.018 s
Explanation:
given,
nerve impulse in human body travel at a speed of = 100 m/s
height of the man = 1.80 m
time taken by the impulse to travel from foot to brain = ?
distance = speed × time
1.80 = 100 × t
t =
t = 0.018 s
hence, the time taken by the nerve to reach brain from toe is 0.018 s
