Answer:
the sides of the wedge are inclined.
Explanation:
The wedge is a triangular simple machine with a blunt face and two inclined faces. The distribution of forces in a wedge is because the sides of the wedge are inclined.
Answer:
a). 6 seconds
b). 12 seconds
c). 176.4 meters
Explanation:
a). Equation to be applied to calculate the time taken by the rocket to reach at the peak height,
v = u - gt
where v = final velocity
u = initial velocity = 58.8 m per sec
g = gravitational pull = 9.8 m per sec²
t = duration of the flight
At the peak height,
v = 0
Therefore, 0 = 58.8 - (9.8)(t)
t = 
= 6 seconds
b). Total time of flight = 2(Time taken to go up)
= 2×6
= 12 sec
c). Formula to get the peak height is,
h = (58.8)6 - 
= 352.8 - 176.4
= 176.4 meters
Answer:
- Distance is a scalar quantity, defined as the total amount of space covered by an object while moving between the final position and the initial position. Therefore, it depends on the path the object has taken: the distance will be minimum if the object has travelled in a straight line, while it will be larger if the object has taken a non-straight path.
- Displacement is a vector quantity, whose magnitude is equal to the distance (measured in a straight line) between the final position and the initial position of the object. Therefore, the displacement does NOT depend on the path taken, but only on the initial and final point of the motion.
If the object has travelled in a straight path, then the displacement is equal to the distance. In all other cases, the distance is always larger than the displacement.
A particular case is when an object travel in a circular motion. Assuming the object completes one full circle, we have:
- The distance is the circumference of the circle
- The displacement is zero, because the final point corresponds to the initial point
Answer:
Concepts and Principles
1- Kinetic Energy: The kinetic energy of an object is:
K=1/2*m*v^2 (1)
where m is the object's mass and v is its speed relative to the chosen coordinate system.
2- Gravitational potential energy of a system consisting of Earth and any object is:
U_g = -Gm_E*m_o/r*E-o (2)
where m_E is the mass of Earth (5.97x 10^24 kg), m_o is the mass of the object, and G = 6.67 x 10^-11 N m^2/kg^2 is Newton's gravitational constant.
Solution
The argument:
My friend thinks that escape speed should be greater for more massive objects than for less massive objects because the gravitational pull on a more massive object is greater than the gravitational pull for a less massive object and therefore the more massive object needs more speed to escape this gravitational pull.
The counterargument:
We provide a mathematical counterargument. Consider a projectile of mass m, leaving the surface of a planet with escape speed v. The projectile has a kinetic energy K given by Equation (1):
K=1/2*m*v^2 (1)
and a gravitational potential energy Ug given by Equation (2):
Ug = -G*Mm/R
where M is the mass of the planet and R is its radius. When the projectile reaches infinity, it stops and thus has no kinetic energy. It also has no potential energy because an infinite separation between two bodies is our zero-potential-energy configuration. Therefore, its total energy at infinity is zero. Applying the principle of energy consersation, we see that the total energy at the planet's surface must also have been zero:
K+U=0
1/2*m*v^2 + (-G*Mm/R) = 0
1/2*m*v^2 = G*Mm/R
1/2*v^2 = G*M/R
solving for v we get
v = √2G*M/R
so we see v does not depend on the mass of the projectile
