Answer:74.33 feet per sec
Explanation:
Given
Police car is 50 feet side of road
Red car is 140 feet up the road
Distance between them is decreasing at the rate of 70 feet per sec
From figure
z=148.66 feet
as the red car is moving
therefore its velocity magnitude is given by
Since no external torques are acting on the skater, his angular momentum must be conserved in the two different situations (arms and legs in - arms out and one leg out). The angular momentum is given by
where I is the moment of inertia and
the angular speed.
Labeling with "1" the situation where the skater has arms and legs in, and with "2" the situation where the skater has arms out and one leg out, the conservation of the angular momentum becomes
or
We know the moment of inertia and the angular speed of the skater when he has arms and legs in:
and also the moment of inertia of the skater when he has arms and one leg out:
so we can find his angular speed when he opens the arms and one leg:
Answer: force = mass x accelegation
Explanation: 15x3 = 45 N
Power = energy / time
Power = 67,500 / 45 = 1,500 joules per second = 1,500 watts = 1.5 kilowatts
Answer:
0.0316 m
Explanation:
Wok done = Energy change
Work done on the spring = Energy change of the block
Elastic Potential stored = Kinetic energy of the block
x =
x =
x = 0.0316 m
k = spring constant
m = mass of block
v = velocity of the block
x = compression of spring