Answer:
632.8 nm is the wavelength (in air) of red light from a helium neon laser.
Answer:
≈ 6.68 m/s
Explanation:
A suitable formula is ...
vf^2 -vi^2 = 2ad
where vi and vf are the initial and final velocities, a is the acceleration, and d is the distance covered.
We note that if the initial launch direction is upward, the velocity of the ball when it comes back to its initial position is the same speed, but in the downward direction. Hence the problem is no different than if the ball were initially launched downward.
Then ...
vf = √(2ad +vi^2) = √(2·9.8 m/s^2·1.0 m+(5 m/s)^2) = √44.6 m/s
vf ≈ 6.68 m/s
The ball hits the ground with a speed of about 6.68 meters per second.
__
We assume the launch direction is either up or down.
Answer:
1600 W
Explanation:
Power is the product of force and distance, divided by time.
P = (120 kg)(10 m/s²)(40 m)/(30 s) = 1600 kg·m²/s³ = 1600 W
Answer:
Work done, W =1520 J
Explanation:
We have,
The brakes on a bicycle apply 95 N of force to the wheels. When the brakes are applied, the bicycle comes to a stop in 16 m.
It is required to find the work done by the brakes on the wheels. We know that the product of force and displacement is equal to the work done. It is given by :
So, the work done by the brakes is 1520 J.