Answer:
skateboard b
Explanation:
p=mv
skateboard a
p=(60kg)(1.5m/s)=90kg*m/s
skateboard b
p=(50kg)(2m/s)=100kg*m/s
Answer:
Drag
Explanation:
It is caused by air resistance and acts in the oooosite direction to the motion.
The answer is 570 J. The kinetic energy has the formula of 1/2mV². The total work in this process W= 1/2m(V2²-V1²) = 1/2 * 15.0 * (11.5²-7.50²) = 570 J.
Just as Prof. Newton said: "For every action, there is an EQUAL, OPPOSITE reaction.". (See his motion law #3.)
If our person APPLIED a force of 80N pointing to the right, then that's the 'action'. It must follow, as the night follows the day, that the strength of the equal REaction is also 80N, and it points to the left because it's opposite to the action.
Answer:
Explanation:
The area of a circle is given b
A=πr²
Then,
dA/dr= 2πr
Also give that,
dr/dt=30m/hr, r=100m
We want to find dA/dt
dA/dt=dA/dr×dr/dt
dA/dt= 2πr × 30
dA/dt= 2 ×π ×100×30
dA/dt=18849.56m²/s.
The rate of the area is 18849.56m²/s