Answer:
The football leaves with the velocity, u = 15.68 m/s
Explanation:
Given data,
The football bounces back up off the ground and is airborne for, t = 3.2 s
Let the football bounces back up off the ground in the vertical direction
The formula for time of flight is given by,
t = 2u /g
∴ u = gt / 2
Substituting the values,
u = 9.8 x 3.2 / 2
u = 15.68 m/s
Hence, the football leaves with the velocity, u = 15.68 m/s
Answer:
60m
Explanation:
According to one of the equation of motions, v² = u²+2as where;
S is the distance
u is the initial velocity
v is the final velocity
a is the acceleration
Since the arrow is shot upwards, the body will experience a negative acceleration due to gravity i.e a = -g
Therefore our equation will become;
v² = u² - 2gS
Given u = 40m/s, g = 10m/s², S = 75m
Substituting to get the final velocity of the arrow we will have;
v² = 40²-2(10)(75)
v² = 1600 - 1500
v² = 100
v = √100
v = 10m/s
Total distance traveled is speed of the object × time taken
Total distance traveled = 10 × 6
= 60m
The arrow has therefore traveled 60m after 6seconds
Answer:
-20000 kgm/s
Explanation:
Impulse: This can be defined as the product of the mass of a body and its change in velocity. The S.I unit of impulse is kgm/s.
Mathematically, impulse can be expressed as
I = m(v-u).............. Equation 1.
Where I = impulse applied to the car to bring it to rest, m = mass of the car, u = initial velocity of the car, v = final velocity of the car.
Given: m = 1000 kg, u = 20 m/s, v = 0 m/s ( to rest)
Substitute into equation 1
I = 100(0-20)
I = 1000(-20)
I = -20000 kgm/s
Hence the impulse applied to the car to bring it to rest = -20000 kgm/s
Answer:
c)is unique to that element
Explanation:
The spectrum emitted by a element shows the internal electronic structure of that element.We know that all element is having different internal electronic structure that is why all element emits different spectrum.And the spacing between the spectrum is uneven .
Therefore the answer will be option C.
c)is unique to that element
