Physics, 18.02.2020 00:24, Campos101

Cousin Milty, aged 93 and of mass 70.0 kg, pulls a 40.0 kg carton of books along his livingroom floor. Consider a period of time during which he pulls the carton at a constant speed of 0.500 m/s, through a distance of 4.00 m along a straight line, while applying a constant force of 200 N directed 30 degrees above the horizontal. Calculate:(a) The work done on the carton by Cousin Milty equals(b) The work done on the carton by the floor’s normal contact force(c) The work done on the carton by the force of gravity

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answered: mallyosburn

a) $W=692.82\ J$

b) 0

c) 0

Explanation:

Given:

mass of person, $m=70\ kg$

mass of books , $m_b=40\ kg$

velocity of pulling the books, $v=0.5\ m.s^{-1}$

distance through which the carton of books is pulled, $s=4\ m$

force applied for pulling, $F=200\ N$

direction of force above the horizontal, $\theta=30^{\circ}$

Now the work done on the carton of books:

$W=F.s\cos\theta$

$W=200\times 4\times \cos30^{\circ}$

$W=692.82\ J$

Since there is no vertical displacement in the carton in vertical direction along which a component of force act, so the work done due to the normal contact force is zero.

Since there is no vertical motion in the carton so the work done will be zero.

answered: Guest

answer and explanation;

composition refers to both the types of minerals within a rock and the overall chemical makeup of the rock while texture refers to the size and arrangement of the minerals or grains that make up a rock. both composition and texture can be used to classify rocks, such as igneous rocks. texture describes how the rock became solid or crystallized from liquid, melted rock. composition of a rock describes the minerals that make up a particular rock.

answered: Guest

m₁v₁ + m₂v₂ = (m₁ + m₂)vmomentum is conserved.the left-hand side of the equation represents the momentum in the system before the collision.the right-hand side represents the momentum in the system after the collisionm₁ and v₁ represents the mass and the velocity of the physics blockm₂ and v₂ represents the mass and velocity of the ball of puttyv represents the final velocity of the combined mass.the question states the two masses stick together. they combined mass has its own velocity with the body mass the sum of the two objects' massestheir combined momentum is (m₁ + m₂)vto find the magitude of (m₁ + m₂)v, we need to add the vectors on the left-hand side of the equation: m₁v₁ + m₂v₂.note the diagram. i have positioned the vectors in accordance with their directions.the magnitude of the resultant can be calculated using the pythagorean theorem since this is a right triangle situation (north and west are perpendicular)|(m₁ + m₂)v| = √[ (m₁v₁)² + (m₂v₂)² ]|(m₁ + m₂)v| = √[ (1.5kg·8.0m/s)² + (0.40kg·20m/s)² ]|(m₁ + m₂)v| = 14.4 kg m/sfor two significant figures (assuming that 20m/s is two), this rounds to 14 kg m/s