I need help answering these questions! Please!

A box of bananas weighing 40.0 NN rests on a horizontal surface. The coefficient of static friction between the box and the surf

mezya [45]

Answer:

a) 0 N

b) 6 N

c) So the applied force must be greater than 16 newton.

Explanation:

Given:

weight of the box, $w=40\ N$

coefficient of static friction between the box and horizontal surface, $\mu_s=0.4$

coefficient of kinetic friction, $\mu_k=0.2$

Here the given value of coefficient of static friction is understated, it is given here as the maximum value of the coefficient of static friction which is variable according to the applied force on the body tending to promote a relative motion between the surfaces.

a)

When no horizontal force is applied on the box and the box is at rest then according to the Newton's first law of motion the box tends to have its initial state of rest and all the forces acting on the box are in equilibrium. Hence no frictional force acts on the box.

b)

When a monkey applies a force of 6 N on the box and it does not move then the contact surface friction also applies the equal amount of force in the opposite direction which balances out the applied force, this will happens upto the maximum coefficient of friction which is stated as coefficient of static friction in the question.

c)

the minimum force required to move the box must be greater than the maximum force of friction which resists the relative motion.

We have the maximum frictional force as:

$f=\mu_s.w$

$f=0.4\times 40$

$f=16\ N$

So the applied force must be greater than 16 newton.

8 0

3 years ago

A horizontal force of magnitude 30.2 N pushes a block of mass 3.50 kg across a floor where the coefficient of kinetic friction i

marshall27 [118]

Answer:

A) 89.39 J

B) 30.39J

C) 23.8 J

Explanation:

We are given;

F = 30.2N

m = 3.5 kg

μ_k = 0.646

d = 2.96m

ΔEth (Block) = 35.2J

A) Work done by the applied force on the block-floor system is given as;

W = F•d

Thus, W = 30.2 x 2.96 = 89.39 J

B) Total thermal energy dissipated by the whole system which includes the floor and the block is given as;

ΔEth = μ_k•mgd

Thus, ΔEth = 0.646 x 3.5 x 9.8 x 2.96 = 65.59J

Now, we are given the thermal energy of the block which is ΔEth (Block) = 35.2J.

Thus,

ΔEth = ΔEth (Block) + ΔEth (floor)

Thus,

ΔEth (floor) = ΔEth - ΔEth (Block)

ΔEth (floor) = 65.59J - 35.2J = 30.39J

C) The total work done is considered as the sum of the thermal energy dissipated as heat and the kinetic energy of the block. Thus;

W = K + ΔEth

Therefore;

K = W - ΔEth

K = 89.39 - 65.59 = 23.8J

3 0

3 years ago

The temperature at a point (x, y) is T(x, y), measured in degrees Celsius. A bug crawls so that its position after t seconds is

Naily [24]

Answer:

$\dfrac{dT}{dt}=59\ ^{\circ}C/s$

Explanation:

Given that

x = 1 + t , y = 9 + 1 3 t

Tx(2, 10) = 7 ,Ty(2, 10) = 4

T=T(x,y)

$\dfrac{dT}{dt}=\dfrac{dT}{dx}\dfrac{dx}{dt}+\dfrac{dT}{dy}\dfrac{d}{dt}$

$T_x=\dfrac{dT}{dx}\ ,T_y=\dfrac{dT}{dy}$

$\dfrac{dx}{dt}=1$

$\dfrac{dy}{dt}=13$

Tx(2, 10) = 7 ,Ty(2, 10) = 4

Now by putting the values

$\dfrac{dT}{dt}=\dfrac{dT}{dx}\dfrac{dx}{dt}+\dfrac{dT}{dy}\dfrac{d}{dt}$

$\dfrac{dT}{dt}=7\times 1+4\times 13\ ^{\circ}C/s$

$\dfrac{dT}{dt}=59\ ^{\circ}C/s$

6 0

3 years ago

When the dog shakes his body, his fur and the droplets of water clinging to it move in circular arcs. If the droplets leave the

AysviL [449]

Answer:

A) True. The droplets will move in parabolic arcs.

Explanation:

When the dog shakes the drops that leave the fur they leave with a speed and an angle; These are now subject to the out of gravity that accelerates them in the vertical axis and has no outside the horizontal axis, so they must describe a parabolic movement.

Pair to describe a central force that changes its speed, but this force does not exist once they leave the dog

Let's check the answers

A) True. You agree with the analysis

B) False. There is an outside on the axis and therefore the line is deviating

C) False. There is no radial force that creates this movement

4 0

3 years ago

What is one example of the use of an infrared sensor?

Bas_tet [7]

If im right it would be c.

7 0

4 years ago

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