Answer & Explanation:
The acceleration due to gravity is about 10 m/s^2.
That means a the speed of a falling object will increase by 10 m/s every second that it falls.
We know that the lamp hits the ground at 15 m/s.
That means the lamp has been falling for
Now we use the formula to calculate the height, where
h is the height
g is the acceleration due to gravity and
t is the time taken to fall a height of h.
h = 1/2 x 10 x 1.5^2 = 11.25 m
Answer:
a) 0.049 m
b) Yes, increase
Explanation:
Draw a free body diagram.
In the y direction, there are three forces acting on the feeder. Two vertical components of the tension forces in each rope pulling up, and weight force pulling down.
Apply Newton's second law to the feeder in the y direction.
∑F = ma
2Ty − mg = 0
Ty = mg/2
Let's say the distance the rope sags is d. The trees are 4m apart, so the feeder is 2m horizontally from either tree. Using Pythagorean theorem, we can find the length of the rope on either side:
L² = 2² + d²
L = √(4 + d²)
Using similar triangles, we can write a proportion using the forces and distances.
Ty / T = d / L
Substitute:
(mg/2) / T = d / √(4 + d²)
Solve for d:
Td = mg/2 √(4 + d²)
T² d² = (mg/2)² (4 + d²)
T² d² = (mg)² + (mg/2)² d²
(T² − (mg/2)²) d² = (mg)²
d² = (mg)² / (T² − (mg/2)²)
d = mg / √(T² − (mg/2)²)
Given m = 2.4 kg and T = 480 N:
d = (2.4) (9.8) / √(480² − (2.4×9.8/2)²)
d = 0.049 m
b) If a bird lands on a feeder, this will increase the tension in the rope to support the bird's weight.
Answer:
20.85 years
Explanation:
2.61 km = 2610 m
2.07 kW = 2070 W
First we need to calculate the potential energy required to take m = kg of rain cloud to an altitude of 2610 m is
With a P = 2070 W power pump, this can be done within a time frame of
or 658037739/(60*60) = 182788 hours or 182788 / 24 = 7616 days or 7616 / 365.25 = 20.85 years
Answer:
motion
Explanation:
when an object moves, it gains kinetic energy. so correct option in motion.
hope it helps!
Answer:
Explanation:
As we know that
also we know that
it is given as
also we can find the magnitude of two vectors as
similarly we have
now we know the formula of dot product as