"with the wind" is a tail-wind, and the speeds are added to get the groundspeed.
"against the wind" is a head-wind, and the windspeed is subtracted from the airspeed.
Supposing the runner is condensed to a point and moves upward at 2.2 m/s.
It takes a time = 2.2/g = 2.2/9.8 = 0.22 seconds to increase to max height.
Now looking at this condition in opposite - that is the runner is at max height and drops back to earth in 0.22 s (symmetry of this kind of motion).
From what height does any object take 0.22 s to fall to earth (supposing there is no air friction)?
d = 1/2gt²= (0.5)(9.8)(0.22)²= 0.24 m
Answer:
27.1 m/s
Explanation:
Given that at a race car driving event, a staff member notices that the skid marks left by the race car are 9.06 m long. The very experienced staff member knows that the deceleration of a car when skidding is -40.52 m/s2.
Using third equation of motion,
V^2 = U^2 + 2aS
Since the car is decelerating, the final velocity V = 0
Substitute all the parameter into the equation above,
0 = U^2 - 2 * 40.52 * 9.06
U^2 = 734.22
U = 
U = 27.096
U = 27.1 m/s approximately
Therefore, the staff member can estimate for the original speed of the race car to be 27.1 m/s if it came to a stop during the skid
Answer:
C
Explanation:
Gravity is the main reason that make our planets to pull each other
Answer:
d = V/E
Explanation:
From the definition, we can say that the electric field strength between the plates of a parallel plate capacitor is
E = v/d
where
E = electric field strength
V = potential difference
d = distance between the plates
On rearranging the equation and making d subject of the formula, we have
d = V/E
From the question, we're given that
V = 112 V
E = 1.12 kV/cm converting to V/m, we have 110000 V/cm
d = 112 / 110000
d = 0.00102 m
d = 1.02*10^-3 m
