What is the width of a professional football field?.

Oliver is designing a new children's slide to increase speed at which a child can descend.His first design involved steel becaus

Ede4ka [16]

Answer:

Steel can rusts easily in the presence of moisture and oxygen, and tarnishes as the rust progresses.

Explanation:

Steel is an alloy of carbon and iron. it is a very useful alloy that is found in almost any engineered piece. The problem with steel is that it is very susceptible to rust, and the cost of maintaining it in order to prevent rust is very high. Steel rusts in the presence of moisture and oxygen (rust is an oxidation-reduction process). Using it as a water slide exposes it constantly to moisture, and to prevent it from rusting in this case will involve a lot of maintenance cost, which is why steel is not advisable to be used in this case.

4 0

3 years ago

Errors in the output voltage of an actual integrated circuit operational amplifier can be caused by : Select one:

natta225 [31]

Answer:

Option B

Explanation:

An operational amplifier usually has a high open loop gain of around 10^5 which allows a wide range get of feed back levels in order to achieve the desired performance so therefore a low open loop gain reduces the range feed back level thereby reducing the performance which can cause errors in the output voltage.

7 0

3 years ago

____________ are calibrated to deliver one fixed volume and are ____________ than ______________. Select one: a. Transfer pipets

LiRa [457]

Answer:

b. Transfer pipets; more accurate; measuring pipets.

Explanation:

Transfer pipets can be defined as an ungraduated or graduated disposable plastic instrument which are typically used in science laboratories to transfer or deliver liquids that are small in volume (microliters) . Also, they are generally being referred to as chemical

droppers, teat pipets, eye droppers, pasteur pipets, or droppers. It is made up of an ultra-clear long, slender tube with low density polyethylene (LDPE) and an integral molded bulb. The molded bulb allows a fixed volume of the desired liquid to be dispensed (transfered) or aspirated through compression and relaxation.

Hence, transfer pipets are calibrated to deliver one fixed volume and are more accurate than measuring pipets because of its long, slender tube which limits errors.

7 0

3 years ago

A motor car is travelling at 144km/h in a 90km/h speed zone .The driver suddenly sees speed camera 80m ahead before the camera c

Kruka [31]

The deceleration required to comply with the speed limit before being caught by the camera is 6.094 meters per square second.

Let assume that the motor car decelerates at constant rate. Given the initial and final speeds ( $v_{o}$ , $v$ ), in meters per second, and travelled distance ( $s$ ), in meters, the deceleration ( $a$ ), in meters per square second, is determined by this formula:

$a = \frac{v^{2}-v_{o}^{2}}{2\cdot s}$

If we know that $v_{o} = 25\,\frac{m}{s}$ , $v = 40\,\frac{m}{s}$ and $s = 80\,m$ , then the deceleration required to comply with the speed limit is:

$a = \frac{\left(25\,\frac{m}{s} \right)^{2}-\left(40\,\frac{m}{s} \right)^{2}}{2\cdot (80\,m)}$

$a = -6.094\,\frac{m}{s^{2}}$

The deceleration required to comply with the speed limit before being caught by the camera is 6.094 meters per square second.

We kindly invite to check this question on uniform accelerated motion: brainly.com/question/12920060

4 0

3 years ago

Block A has mass of mA = 58kg and rests on a flat surface. The coefficient of static friction between the block and the surface

lesantik [10]

Answer:

The greatest mass, that the weight C can have such that block A does not move is approximately 23.259 kg

Explanation:

The given parameters are;

The mass of the block A= 58 kg

The coefficient of static friction between the block and the surface, $\mu _s$ = 0.300

The coefficient of static friction between the rope and the fixed peg, B $\mu _B$ = 0.310

Let T represent the tension in the rope

Therefore, when the rope is static, T = The normal reaction at the peg, B, $N_B$

The angle of inclination of the rope holding the block A = arctan(3/4) ≈ 36.87°

The length of the rope = √(0.4² + 0.3²) = 0.5

∴ sin(θ) = 3/5 = 0.6

cos(θ) = 4/5 = 0.8

The vertical component of the tension in the rope = T × sin(θ) = 0.6·T

The horizontal component of the tension in the rope = T × cos(θ) = 0.8·T

The friction force = μ×(W - 0.6·T) = 0.300×(58×9.8 - 0.6·T) = 170.52 - 0.18·T

The block will start to move when we have;

The horizontal component of the tension in the rope = The friction force

∴ 0.8·T = 170.52 - 0.18·T

0.8·T + 0.18·T = 170.52

0.98·T = 170.52

T = 170.52/0.98 = 174

Therefore, the tension in the rope = T = 174 N = The normal reaction at the peg, B $N_B$

The frictional force at the peg, $F_B$ = $\mu _B$ × $N_B$ = 0.310 × 174 N = 53.94 N

The weight of the mass, $m_c$ , $W_c$ = The frictional force at the peg, $F_B$ + The tension in the rope

∴ The weight of the mass, $m_c$ , $W_c$ = 53.94 N + 174 N = 227.94 N

Weight, W = Mass, m × The acceleration due to gravity, g, from which we have;

m = W/g

Where;

g = 9.8 m/s²

∴ $m_c$ = $W_c$ /g = 227.94 N/(9.8 m/s²) ≈ 23.259 kg.

The greatest mass, that the weight C can have such that block A does not move = $m_c$ ≈ 23.259 kg.

4 0

3 years ago