Because "velocity" means the speed and direction of the motion.
In circular motion, or motion on any curved path, the direction is constantly changing. So even if the speed isn't changing, the <em>velocity</em> is.
Go to what your heart says
Answer:
B) 2 times what it now is
Explanation:
The acceleration due to gravity at the surface of the Earth is given by
![g=\frac{GM}{R^2}](https://tex.z-dn.net/?f=g%3D%5Cfrac%7BGM%7D%7BR%5E2%7D)
where
G is the gravitational constant
M is the mass of the Earth
R is the Earth's radius
In this problem, the mass of the Earth is doubled:
M' = 2M
while the radius remains the same:
R' = R
so the new acceleration due to gravity would be
![g'=\frac{GM'}{R'^2}=\frac{G(2M)}{R^2}=2\frac{GM}{R^2}=2g](https://tex.z-dn.net/?f=g%27%3D%5Cfrac%7BGM%27%7D%7BR%27%5E2%7D%3D%5Cfrac%7BG%282M%29%7D%7BR%5E2%7D%3D2%5Cfrac%7BGM%7D%7BR%5E2%7D%3D2g)
so, the acceleration due to gravity would become twice the current value.
Note also that the value of g does not depend on the mass of the objects involved.
Answer:
= 8.46 × 10³N
Explanation:
W = 1.3 × 10⁴
v₁ = 0
v (friction) = 95km/h = 26.4 m/s
t = 5s
f = 1450N
mass of body = W / g
=1.3 × 10⁴ / 9.8
=1327 kg
v(friction) = v + at
substitute in eqn 1
26.4 = 5a
a = 5.28 m/s
Force Net = F₁ + F₂ + F₃ = ma
F (engine) = ma + F
= 1327 (5.28) + 1450
= 8.46 × 10³N