Answer:
a. 79.1 N
b. 344 J
c. 344 J
d. 0 J
e. 0 J
Explanation:
a. Since the crate has a constant velocity, its net force must be 0 according to Newton's 1st law. The push force by the worker must be equal to the friction force
on the crate, which is the product of friction coefficient μ and normal force N:
Let g = 9.81 m/s2
b. The work is done on the crate by this force is the product of its force and the distance traveled s = 4.35
c. The work is done on the crate by friction force is also the product of friction force and the distance traveled s = 4.35
This work is negative because the friction vector is in the opposite direction with the distance vector
d. As both the normal force and gravity are perpendicular to the distance vector, the work done by those forces is 0. In other words, these forces do not make any work.
e. The total work done on the crate would be sum of the work done by the pushing force and the work done by friction
Answer:
Explanation:
First displacement of the particle is given as
= 11 m at 82 degree with positive X axis
so we can say
resultant displacement of the particle after second displacement is given as
r = 8.7 m at 135 degree with positive X axis
so we can say
now we know that
now we have
so we will have
so angle of the second displacement is given as
Answer:
mass = 0.44 Kg
Explanation:
given,
Calories contain in the strawberry yogurt = 255 calories
1 Calorie = 4186 J
latent heat of vaporization = 2.42 x 10⁶ J/Kg
mass of perspiration = ?
Energy = 255 calories
Energy = 255 x 4186
= 1067430 J
Energy = mass x latent heat of vaporization
mass = 0.44 Kg
The question is incomplete. The complete question is :
If the entire population of Earth were transferred to the Moon, how far would the center of mass of the Earth-Moon population system move? Assume the population is 7 billion, the average human has a mass of 65 kg, and that the population is evenly distributed over both the Earth and the Moon. The mass of the Earth is 5.97×1024 kg and that of the Moon is 7.34×1022 kg. The radius of the Moon’s orbit is about 3.84×105 m.
Solution :
Given :
Mass of earth,
Mass of moon,
Mass of each human,
Therefore mass of total population,
Let the earth is at the origin of the coordinate system. Then,
Since
Hence if we shift all the population on the moon there will be negligible change in the mass of the moon and earth. Hence there will not be any significant shift on the centre of mass. i.e.
from the earth.
