Answer:
(a): It spends on the trip 2.75 hr (2 hours 45 minutes)
(b): The person travels 213.9 km.
Explanation:
Vp= 77.8 km/h
V1= 89.5 km/h
V2= 0 km/h
t2= 0.36hr
t1= ?
Vp= (V1*t1 + V2*t2) / (t1 + t2)
clearing t1:
t1= 2.39 hr
Trip time= t1+t2
Trip time= 2.75 hr (a)
Distance traveled= V1*t1
Distace traveled= 213.9 km (b)
Answer: 1100 W
Explanation:
Input power = 220(5) = 1100 W
The transformer will step up/down voltage, but will also step down/up current.
Neglecting hysteresis and other minor losses, the power will remain the same.
No I do not agree. It is because work is done when force acting o a body displace or covers certain displacement in the direction of force applied .
Explanation:
For this problem, use the first law of thermodynamics. The change in energy equals the increase in heat energy minus the work done.
ΔU=Q−W
We are not given a value for work, but we can solve for it using the force and distance. Work is the product of force and displacement.
W=FΔx
W=3N×2m
W=6J
Now that we have the value of work done and the value for heat added, we can solve for the total change in energy.
ΔU=Q−W
ΔU=10J−6J
ΔU=4J
Answer is 4J
i think this may help you very much
Ok so use trigonometry to work out the vertical component of velocity.
sin(25) =opp/hyp
rearrange to:
30*sin(25) which equals 12.67ms^-1
now use SUVAT to get the time of flight from the vertical component,
V=U+at
Where V is velocity, U is the initial velocity, a is acceleration due to gravity or g. and t is the time.
rearranges to t= (V+u)/a
plug in some numbers and do some maths and we get 2.583s
this is the total air time of the golf ball.
now we can use Pythagoras to get the horizontal component of velocity.
30^2-12.67^2= 739.29
sqrt739.29 = 27.19ms^-1
and finally speed = distance/time
so--- 27.19ms^-1*2.583s= 70.24m
The ball makes it to the green, and the air time is 2.58s