Answer:
External force on him will be 112 N
Explanation:
We have given the mass of the sprinter m =70 kg
Acceleration of the sprinter 
We have to find the net external force
According to second law of motion force = mass ×acceleration
Force is dependent on the mass and acceleration
So 
So external force will be 112 N
Answer with Explanation:
We are given that
Diameter of fighter plane=2.3 m
Radius=
a.We have to find the angular velocity in radians per second if it spins=1200 rev/min
Frequency=
1 minute=60 seconds
Angular velocity=
Angular velocity=
b.We have to find the linear speed of its tip at this angular velocity if the plane is stationary on the tarmac.

c.Centripetal acceleration=
Centripetal acceleration==
Answer:
600 J
Explanation:
The formula to find the kinetic energy of an object is
- m = mass in kg
- V = velocity in m/s
- KE is measured in Joules just as all other forms of energy.
Now, let's plug in the variables we're given and simplify.
Thus, the answer is 600 Joules.
Answer:
c 275 m
Explanation:
Given parameters:
Final velocity = 73.5m/s
Unknown:
Height of fall = ?
Solution:
Since the body is falling from rest, U = 0 or initial velocity is 0m/s. Then we use one of the kinematics equation to solve this problem.
V² = U² + 2gH
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity
H is the height
73.5² = 0² + (2 x 9.8 x h)
5402.25 = 19.6h
h = 275.6m