The first thing you should know is that acceleration is a vector, therefore, it has magnitude, and direction.
By definition, we have that the vector acceleration is given by:
Where,
dv/dt: derived from the velocity vector with respect to time,
Therefore, the units of the vector acceleration are:
The symbol of acceleration is:
Answer:
The statements about acceleration that are true are:
a. the si units of acceleration are m/s2.
b. for acceleration, you must have a number, a unit, and a direction.
d. the symbol for acceleration is (True, only if the symbol is the same as above)
Answer:
The percentage of its mechanical energy does the ball lose with each bounce is 23 %
Explanation:
Given data,
The tennis ball is released from the height, h = 4 m
After the third bounce it reaches height, h' = 183 cm
= 1.83 m
The total mechanical energy of the ball is equal to its maximum P.E
E = mgh
= 4 mg
At height h', the P.E becomes
E' = mgh'
= 1.83 mg
The percentage of change in energy the ball retains to its original energy,
ΔE % = 45 %
The ball retains only the 45% of its original energy after 3 bounces.
Therefore, the energy retains in each bounce is
∛ (0.45) = 0.77
The ball retains only the 77% of its original energy.
The energy lost to the floor is,
E = 100 - 77
= 23 %
Hence, the percentage of its mechanical energy does the ball lose with each bounce is 23 %
For these question, it has two separate equations: 2f(a) and f(2a) .
For f(2a) equations its x=2a, so you must substitute 2a into the f(x) equation
For 2f(a), it means the two time of f(a) equation with x=a, so you substitute a inti f(x) equation first, then you multiply it by 2.
Answer:
2.27kg
Explanation:
The Potential energy gained = Force gravity× Height
Force gravity on the ball is GPE/ height
56.8/2.5=22.72N
the mass = 22.72/10= 2.27kg
Answer:
48 hours
Explanation:
Using the formula,
R/R' = 2ᵃ/ᵇ..................... Equation 1
Where R = Original amount, R' = Radioactive remain, a = Total time, b = half life.
Given: b = 24 hours,
Let: R = X, then R' = X/4.
Substitute into equation 1
X/(X/4) = 2ᵃ/²⁴
4 = 2ᵃ/²⁴
2² = 2ᵃ/²⁴
Equating the base and solving for a
2 = a/24
a = 24×2
a = 48 hours.
Hence the time = 48 hours
