a)The average acceleration of the car is
b) The distance travelled is 560 m
<u>Explanation:
</u>
a) Acceleration is defined as the rate of change in velocity per unit time. So it can be obtained by measuring the ratio of speed to time.
Since here the initial speed was zero and final speed is given as 28 m/s, then time is given as 20 s. So,
b) As the speed is given as 28 m/s, then
So the distance travelled is 560 m and average acceleration is .
Work= force (N) x distance (m)
F= mass (kg) x acceleration (gravity; m/s^2)
for this question, your formula would be
Work= mass (kg) x acceleration (gravity) x distance (m)
a. F=20kg x 9.81 m/s^2 x6 m = 1177.2 J
b. F=25kg x 9.81 m/s^2 x3 m = 735.75 J
c. F=25kg x 9.81 m/s^2 x6 m = 1471.5 J
d. F=50kg x 9.81 m/s^2 x1 m = 490.5 J
Tip:
- If this was a timed test, you could save some time by just multiplying the mass (kg) in the question by the distance because 9.81 is a constant in the formula, you can ignore it (+you're not asked for the final answer). c would still be the largest number
- it would also help if you noticed:
- the distance in c is half that of b but the mass is the same. eliminate b because c is obviously bigger
- a and c have the same distance but 25 is greater than 20; eliminate a
Potential energy is proportional to the object's mass, and to the height
to which it's lifted. If the heights are the same, then it depends only on
the mass, and the 4-kg object has more potential energy at that height.
How long it took each one to arrive at that height is a totally irrelevant
consideration.
Answer:
it increases by a factor 1.07
Explanation:
The peak wavelength of an object is given by Wien's displacement law:
(1)
where
b is the Wien's displacement constant
T is the temperature (in Kelvins) of the object
given the relationship between frequency and wavelength of an electromagnetic wave:
where c is the speed of light, we can rewrite (1) as
So the peak frequency is directly proportional to the temperature in Kelvin.
In this problem, the temperature of the object changes from
to
so the peak frequency changes by a factor
C i’m pretty sure cuz the rest of them happen after