Answer:
a) 2.94 N
b) 4.90 N
Explanation:
Let us assume that the weight of the ball is 0.98 N
Solution:
a) An object’s gravitational potential energy depends on two factors which are height and its weight (or mass). The equation for gravitational potential energy (PE) is given as:
Potential energy = weight (w) * height (h)
PE = wh
Potential energy at 2 m shelf = weight * height = 0.98 N * 2 m = 1.96 N
Potential energy at 5 m shelf = weight * height = 0.98 N * 5 m = 4.90 N
The work needed to lift the ball from the 2-m shelf to the 5-m shelf = Potential energy at 5 m shelf - Potential energy at 2 m shelf
The work needed to lift the ball from the 2-m shelf to the 5-m shelf = 4.90 N - 1.96 N = 2.94 N
b) Potential energy at 5 m shelf = weight * height = 0.98 N * 5 m = 4.90 N
Answer:
I will answer this in English.
He has 45 years.
a year has 365 days.
a day has 24 hours.
So he has:
45*365*24 hours = 394,200 hours.
His mass is 78 kg,
And we know that 1 slug = 1lbf*ft/s^2
Then, the first step is transform the 78 kg into lbf.
1kg = 2.2 lbf.
then 78kg = 78*2.2 lbf = 171.6lbf.
Now, the weight is m*g, where m is the mass and g is the gravitational acceleration, in this case the gravitational acceleration in ft/s^2 is:
g = 32.2 ft/s^2
Then the weight in slugs is:
W = 32.2ft/s^2*171.6lbf = 5,525.5 slugs
According to Doppler Effect, an observer at rest will perceive a shift in the wavelength or frequency of the radiation emitted by a source in movement.This shift is given by the formula:
where:
= observed wavelength
= wavelength at rest
v = speed of source (positive if towards the observer, negative if away from the observer)
c = speed of light
Therefore, we can solve for the observed wavelength:
Substituting the given data:
= 655.80 nm
Hence, the observed wavelength of the line would be
655.80 nm. Note that this value is smaller than the one at rest, which means that we have a blue-shift, as expected for an approaching source.
<span>Alice and Tom will reach the surface of the lake at the same time.
In this problem. Both Alice and Tom have 2 components to their velocities. A horizontal component and an increasing vertical component due to gravity. They start out with different horizontal components, but that component does not in any way contribute to their vertical velocities. Since they both started out at the same height and the same vertical velocities, they will reach the surface of the lake at the same time.</span>
