Answer:
a = 12.8 m/s^2
Explanation:
To find the centripetal acceleration you use the following formula:
(1)
v: tangential speed of the rock = 17.90mph
r: radius of the orbit = 1000cm/2 = 500cm = 0.5m
You first change the units of the tangential velocity in order to replace the values of v and r in the equation (1):
Then, you use the equation (1):
hence, the centripetal acceleration is 12.8 m/s^2
It's downward vector from the centre of apple in the direction to the centre of the Earth.
The deceleration experienced by the gymnast is the 9 times of the acceleration due to gravity.
Now from Newton`s first law, the net force on gymnast,
Here, W is the weight of the gymnast and a is the acceleration experienced by the gymnast ( acceleration due to gravity)
Therefore,
OR
Given and
Substituting these values in above formula and calculate the force exerted by the gymnast,
Answer:
Approximately .
Explanation:
The formula for the kinetic energy of an object is:
,
where
- is the mass of that object, and
- is the speed of that object.
Important: Joule () is the standard unit for energy. The formula for requires two inputs: mass and speed. The standard unit of mass is while the standard unit for speed is . If both inputs are in standard units, then the output (kinetic energy) will also be in the standard unit (that is: joules,
Convert the unit of the arrow's mass to standard unit:
.
Initial of this arrow:
.
That's the same as the energy output of this bow. Hence, the efficiency of energy transfer will be:
.