Answer:
28.2 m/s
Explanation:
The range of a projectile launched from the ground is given by:

where
v is the initial speed
g = 9.8 m/s^2 is the acceleration of gravity
is the angle at which the projectile is thrown
In this problem we have
d = 81.1 m is the range
is the angle
Solving for v, we find the speed of the projectile:

Answer:We can solve this using the Law of Conservation of Momentum. If both marbles are in our system, the initial momentum should equal the final momentum.
The initial momentum can be solved for as so:
* + =
(0.06)(0.7) + (0.03)(0) = 0.042 [kg * m/s]
So if the system has an initial momentum of 0.042, it should have the same final momentum.
(0.06)(-0.2) + (0.03)() = 0.042
(0.03)() = 0.54
() = 18 [m/s]
Explanation:
Answer:
It reduces the melting point due to a defect in the arrangement of the crystal lattice.
Explanation:
The presence of impurities creates a disorderliness in the uniformity of the crystal structure. It lowers the melting point by a few degrees because it becomes easier to overcome the intermolecular force of attraction.
It makes the array of crystals disordered.
Lattice is a long chain three-dimensional arrangement of the molecules, atoms or ions in a crystal structure.
Answer:
161.86 N
Explanation:
mass of box m= 55.0 kg
weight of the box, mg= 55×9.81
g here is acceleration due to gravity =9.81 m/sec^2
coefficient of friction between the box and the surface μ= 0.3
the friction force F_s= μmg= 0.3×55×9.81
=161.86 N
to move the ball horizontal force required is 161.86 N