Please help ASAP!

What is the farthest distance at which a typical "nearsighted" frog can see clearly in air?

Umnica [9.8K]

Answer: the correct option is D (17m).

Explanation: The farthest distance at which a typical "nearsighted" frog can see clearly in air is 17m.

7 0

4 years ago

a man drags a 8.10 kg bag of mulch at a constant speed, applying a 29.5 N at 38°. what is the coefficient of friction?

lesantik [10]

Answer:

The coefficient of friction is 0.38.

Explanation:

The free body diagram is drawn below.

Let $f$ be frictional force acting in the backward direction as shown. Let the coefficient of friction be $\mu$ . Let $N$ be the normal reaction force acting on the bag.

Given:

Mass of the bag is, $m=8.10\textrm{ kg}$

Force acting at $\theta = 38$ ° is $F= 29.5\textrm{ N}$

Acceleration due to gravity is, $g=9.8\textrm{ }m/s^{2}$

The force F can be resolved into its components as $F_{x}=F \cos \theta$ and $F_{y}=F \sin \theta$

Therefore,

$F_{x}=29.5\cos(38)=23.25\textrm{ N}\\F_{y}=29.5\sin(38)=18.16\textrm{ N}$

Now, as there is no acceleration in vertical direction, therefore,

Sum of upward forces = Sum of downward forces

$N+F_{y}=mg\\N=mg-F_{y}=8.10\times 9.8-18.16\\N=79.38-18.16=61.22\textrm{ N}$

Now, as the bag is moving at a constant speed, so acceleration in the horizontal direction is also zero as acceleration is the rate of change of velocity.

Therefore, backward force = forward force.

$f=F_{x}\\f=23.25\textrm{ N}$

Now, frictional force is given as:

$f=\mu N\\\mu = \frac{f}{N}=\frac{23.25}{61.22}=0.38$

Therefore, the coefficient of friction is 0.38.

8 0

4 years ago

Refraction or the bending of waves takes place when a light wave changes A) color. B) frequency. C) intensity. D) speed.

DENIUS [597]

The answer is D. speed

6 0

4 years ago

Read 2 more answers

6. A water brake copupled to an engine on test absorbs 70 kW of power. Find the heat generated at the brake per minute and the m

PtichkaEL [24]

Answer:

4200 kJ

10 kg/min

Explanation:

70 kW means 70 kJ per second. So in a minute, the amount of heat generated at the brake is:

70 kJ/s × 60 s/min = 4200 kJ

Heat = mass × specific heat capacity × increase in temperature

4200 kJ = m × 4.184 kJ/kg/C × 100 C

m = 10 kg

So every minute, 10 kg of water is heated. So the mass flow is 10 kg/min.

7 0

3 years ago

A ball is thrown vertically upward, which is the positive direction.A little later it returns to its point of release.The ball i

vivado [14]

Answer:

u=78.4m/s

Explanation:

A ball is thrown vertically upward, which is the positive direction.A little later it returns to its point of release.The ball is in the air for a total time of 8.0 s.What is its initial velocity? Neglect air resistance

from newtons equation of motion

s=ut $+\frac{1}{2}at^{2}$

v=u+at

v=0 because at maximum height reached by the ball the ball stops moving

0=u-9.8*8

u=78.4m/s

u=initial velocity

v=final velocity

a=acceleration due to gravity, 9.81m/s^2

t=time it takes in air

s= distance to get to the maximum before returning

3 0

3 years ago