Answer:
No
Explanation:
The fastest recorded time for a person to run 100 metres is 9.58 seconds, which is the equivalent of 10.4 metres per second
Answer:
Part a)
acceleration = -0.042 m/s/s
Part b)
initial speed = 14.17 m/s
final speed = 5.77 m/s
Explanation:
Part a)
Let the initial velocity of the motorcycle is

now at the end of 80 s let the speed is

after another 120 s let the speed will be

now we know that



also we know that

also we have


now we can say

also we know



Part b)
now we have



so the starting velocity of the trip is

now speed after t = 200 s is given as



Answer:
D
Explanation:
P=Work/Time
The rate at which work is done matches that.
Answer:
a. 120 W
b. 28.8 N
Explanation:
To a good approximate, the only external force that does work on a cyclist moving on level ground is the force of air resistance. Suppose a cyclist is traveling at 15 km/h on level ground. Assume he is using 480 W of metabolic power.
a. Estimate the amount of power he uses for forward motion.
b. How much force must he exert to overcome the force of air resistance?
(a)
He is 25% efficient, therefore the cyclist will be expending 25% of his power to drive the bicycle forward
Power = efficiency X metabolic power
= 0.25 X 480
= 120 W
(b)
power if force times the velocity
P = Fv
convert 15 km/h to m/s
v = 15 kmph = 4.166 m/s
F = P/v
= 120/4.166
= 28.8 N
definition of terms
power is the rate at which work is done
force is that which changes a body's state of rest or uniform motion in a straight line
velocity is the change in displacement per unit time.
Given Information:
slope angle = θ = 30°
spring constant = k = 30 N/m
compressed length = x = 10 cm = 0.10 m
mass of ice cube = m = 63 g = 0.063 kg
Required Information:
distance traveled by ice cube = d = ?
Answer:
distance traveled by ice cube = 0.48 m
Explanation:
Using the the principle of conversation of energy, the following relation holds true for this case,
mgh = 1/2*kx²
h = 1/2*kx²/mg
Where h is the height of the slope, m is the mass of ice cube, k is the spring constant and x is the compressed length o the spring and g is gravitational acceleration.
h = 1/2*kx²/mg
h = 1/2*30(0.1)²/0.063*9.8
h = 0.242 m
From trigonometry ratio,
sinθ = h/d
d = h/sinθ
d = 0.242/sin(30)
d = 0.48 m
Therefore, when the ice cube is released, it will travel a total distance 0.48 up the slope before reversing direction.