Answer:
Explanation:
Although there is absolutely NO regard for significant digits, I can help you with this, nonetheless.
The equation for Potential Energy is PE = mgh. We have everything but the height of the ball. We have to solve for that using a one-dimensional motion equation:
v² = v₀² + 2aΔx, where Δx is our displacement (the height we need for PE). Filling in and keeping in mind that at the max height of parabolic travel, the final velocity of the object is 0:
0 = (21.5)² + 2(-9.8)Δx and
0 = 462.25 - 19.6Δx and
-462.25 = -19.6Δx so
Δx = 23.58 m. Using this as the h in our PE equation:
PE = .19(9.8)(23.58) so
PE = 43.9 J, choice C.
Answer:
a. If an object's speed is constant, then its acceleration must be zero.
FALSE
As we know that acceleration is defined as the rate of change in velocity
so we can not say anything about the acceleration when speed is given to as and no information is given about velocity
b. If an object's acceleration is zero, then its speed must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity
Since we know that if acceleration is 0 then velocity must be constant and hence speed is also constant
c. If an object's velocity is constant, then its speed must be constant.
TRUE
Since velocity is constant then it shows that its magnitude and direction both are constant so its speed is also constant.
d. If an object's acceleration is zero, its velocity must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity
Since we know that if acceleration is 0 then velocity must be constant
e. If an object's speed is constant, then its velocity must be constant.
FALSE
Speed is just the magnitude so we can not say about its direction and hence if speed is constant then velocity may or may not change
Answer:
Chemical energy is the potential of a chemical substance to undergo a chemical reaction to transform into other substances. Examples include batteries, food, gasoline, and etc. Breaking or making of chemical bonds involves energy, which may be either absorbed or evolved from a chemical system
Answer:
700 m.
Explanation:
Wavelength: This can be defined as the distance in meter required by a wave to complete one oscillation. The S.I unit of of wavelength is meter (m).
the expression connecting velocity, frequency and wavelength is given as,
v = λf......................... Equation 1
Where v = velocity of the earthquake, λ = wavelength of the earthquake, f = frequency of the earthquake.
make λ the subject of the equation
λ = v/f ................. Equation 2
recall,
v = distance/time
v = d/t ................. Equation 2
Where d = distance, t -= time.
Given: d = 84 km = 84000 m, t = 12 s.
Substitute into equation 2
v = 84000/12
v = 7000 m/s.
Also given: f = 10 Hz.
Substitute into equation 2
λ = 7000/10
λ = 700 m.
Hence the wavelength of the earthquake = 700 m.
