Answer:
6.37 x 10³ Km
Explanation:
given,
Radius of earth = 6,370,000 m
we know,
1 km = 1000 m
1 m = 0.001 Km
6,370,000 m = 6,370,000 x 0.001
= 6,370 Km
The number 6,370 has 3 significant figure.
To transform this to an exponential number, it is necessary to move the decimal to the left so there is only one digit in front of the decimal point.
Representing the given number in scientific notation
= 6.37 x 10³ Km
Answer:
The speed of the bob when it passes the lowest point 
Explanation:
Given data
When a pendulum swinging back & forth then at highest point the velocity is zero and lowest point velocity is maximum.
Velocity at lowest point is given by
Therefore the speed of the bob when it passes the lowest point
Wave speed= Frequency x Wavelength
-> Wavelength= Wave speed divide Frequency
-> 50m/s divide 100Hz= 0.5m
why does the baseball have to be autographed?
Answer:
See below
Explanation:
At point A the PE = mgh = 2 * 10 * 1 = 20 J
at point B, all of the PE , 20 J , is converted to Kinetic Energy
KE = 1/2 m v^2
20 = 1/2 (2)(v^2 )
20 = v^2 v = sqrt 20 = 4.47 m/s
for the friction part
vf = vo t + 1/2 a t^2 vf = final velocity = 0 (stopped)
vo = original velocity = 4.47 m/s
a = -1 m/s^2
0 = 4.47 t + 1/2 (-1) t^2
- .5t^2 + 4.47 t = 0
t ( -.5t+ 4.47) = 0 shows t = 4.47/.5 = 8.9 seconds
