A. 90km/h = 25 m/s
W=1/2mv^2
=1/2* 650* 25^2
= 203125(J)
b. v’= 90-50= 40km/h
= 100/9 m/s
W=1/2mv^2
=1/2*650*(100/9)^2
= 40123,45679
Answer:
2.35 s
Explanation:
The period of a simple pendulum is expressed as;
T = 2π
Where
T is the period in seconds
L is the length in metres
g is acceleration due to gravity
T = 2π
T = 2.349 s
T = 2.35 s
Answer:
The jumper is in freefall for 12.447 seconds.
Explanation:
Let's start by calculating how far the jumper falls.
Initial height (on cliff) = 910 m
Final height after freefall = 150 m
Distance the jumper falls in freefall = 910 - 150 = 760 m
We can now use the equation of motion below to solve for the time:

here. acceleration = 9.81 m/s (due to gravity)
initial speed (u) = 0 m/s (because vertical speed is 0 at the start)
and distance (s) = 760 meters (as calculated above)
So for speed we get:


t = 12.447 seconds
De-celleration because speed is lower as time goes on
Answer:
$84
Explanation:
The coefficient of performance (COP) show the relationship between the power (kW) output of the heat pump and the power (kW) input to the compressor.
The heater consumed by the heater is 1200 kWh.
For a heat pump with a COP of 2.4, the electric input needed to produce an output of 1200 kWh is:
Electric input to heat pump = 1200 / 2.4 = 500 kWh
That means that supplying a heat pump with 500 kWh produces an output of 1200 kWh
The amount of power saved = power consumed by heater - power consumed by heat pump = 1200 - 500 = 700 kWh
Money saved = $0.12/kWh * 700 kWh = $84