Answer:
a. 4
Explanation:
Hi there!
The equation of kinetic energy (KE) is the following:
KE = 1/2 · m · v²
Where:
m = mass of the car.
v = speed of the car.
Let´s see how would be the equation if the velocity is doubled (2 · v)
KE2 = 1/2 · m · (2 · v)²
Distributing the exponent:
KE2 = 1/2 · m · 2² · v²
KE2 = 1/2 · m · 4 · v²
KE2 = 4 (1/2 · m · v²)
KE2 = 4KE
Doubling the velocity increased the kinetic energy by 4.
a) 10 m/s
b) 25 m
Explanation:
a)
The body is moving with a constant acceleration, therefore we can solve the problem by using the following suvat equation:
where
u is the initial velocity
v is the final velocity
a is the acceleration
t is the time
For the body in this problem:
u = 0 (the body starts from rest)
is the acceleration
t = 5 s is the time
So, the final velocity is
b)
In this second part, we want to calculate the distance travelled by the body.
We can do it by using another suvat equation:
where
u is the initial velocity
v is the final velocity
a is the acceleration
s is the distance travelled
Here we have
u = 0 (the body starts from rest)
is the acceleration
v = 10 m/s is the final velocity
Solving for s,
Answer:
Explanation:
Let the first height be h . second height .75h
third height .75h . fourth height .75²h
fifth height .75²h , sixthth height .75³ and so on
Total distance consists of two geometric series as follows
1 ) first series
h + .75h + .75²h + .75³h......
2 ) second series
.75h +.75²h +.75³h + .75⁴h .......
Sum of first series :
first term a = h , commom ratio r = .75
sum = a / (1 - r )
= h / 1 - .75
= h / .25
4h
sum of second series :--
first term a = .75 h , commom ratio r = .75
sum = a / (1 - r )
= .75h / 1 - .75
= .75h / .25
3h
Total of both the series
= 4h + 3h
= 7h .
h = 1 m
Total distance = 7 m
<h3><u>Answer</u>;</h3>
C. An object can have acceleration with negative velocity.
<h3><u>Explanation</u>;</h3>
- Acceleration is a measure of the change in velocity over time. The change in velocity is measured in meter per second (m/s), and time interval is measured in second (s).
- Therefore, acceleration measures the change in meters per second every second [(m/s)/s], namely meters per second per second or meters per second squared (m/s2).
- If an object has zero acceleration, its velocity doesn’t have to be zero. Acceleration is a measure of the change in velocity over time. Zero acceleration means there is no change in velocity over time, namely constant velocity.
