Answer:
hold on let me check my answer
Explanation:
Answer:
7066kg/m³
Explanation:
The forces in these cases (air and water) are: Fa =mg =ρbVg Fw =(ρb −ρw)Vg where ρw = 1000 kg/m3 is density of water and ρb is density of the block and V is its density. We can find it from this two equations:
Fa /Fw = ρb / (ρb −ρw) ρb = ρw (Fa /Fa −Fw) =1000·(1* 21.2 /21.2 − 18.2)
= 7066kg/m³
Explanation:
Answer: It takes 2.85 seconds.
Explanation: according to the question, the kinematics equation for vertical motion is

y₀ is the initial postion and equals 0 because it is fired at ground level;
v₀ is the initial speed and eqauls 14m/s;
g is gravity and it is 9.8m/s²;
y(t) is the final position and equals 0 because it is when the pumpkin hits the ground;
Rewriting the equation, we have:
0 + 14t -
= 0
14t - 4.9t² = 0
t(14 - 4.9t) = 0
For this equation to be zero,
t = 0 or
14 - 4.9t = 0
- 4.9t = - 14
t = 
t = 2.86
It takes 2.86 seconds for the pumpkin to hit the ground.
Answer:
C)Earth's orbital speed is greater when it is closer to the Sun than when it is farther from the Sun.
Explanation:
We can use Kepler's 2nd law or the law of area to answer this question.
The law states that the rate of area swept out by a planet's orbit is same throughout the orbit. For the farthest point since the distance is large as compared to to the nearest point, the possibility that area swept is large. Hence, to compensate the extra swept area. the orbital speed has to decrease at the largest point.
Hence, planet's speed is greater when it is closer to sun than the speed when it is farther.
Answer:
The electron’s velocity is 0.9999 c m/s.
Explanation:
Given that,
Rest mass energy of muon = 105.7 MeV
We know the rest mass of electron = 0.511 Mev
We need to calculate the value of γ
Using formula of energy


Put the value into the formula


We need to calculate the electron’s velocity
Using formula of velocity




Put the value into the formula



Hence, The electron’s velocity is 0.9999 c m/s.