It takes a truck 3.56 seconds to slow down from 112 km/h to 87.4 km/h. What is its average acceleration?

Erica throws a tennis ball against a wall, and it bounces back. Which force is responsible for sending the ball back to Erica?

Anna71 [15]

OPTIONS :

A.) the force that the ball exerts on the wall

B.) the frictional force between the wall and the ball

C.) the acceleration of the ball as it approaches the wall

D.) the normal force that the wall exerts on the ball

Answer: D.) the normal force that the wall exerts on the ball

Explanation: The normal force acting on an object can be explained as a force experienced by an object when it comes in contact with a flat surface. The normal force acts perpendicular to the surface of contact.

In the scenario described above, Erica's tennis ball experiences an opposite reaction after hitting the wall.This is in relation to Newton's 3rd law of motion, which states that, For every action, there is an equal and opposite reaction.

The reaction force in this case is the normal force exerted on the ball by the wall perpendicular to the surface of contact.

8 0

2 years ago

Beryllium has a charge of 2, and bromine has a charge of –1. which is the best name for the ionic bond that forms between them?

Otrada [13]

The best name for the ionic bond that forms between them is Beryllium Bromide.

We have been provided with data,

Beryllium charge, q = 2

Bromine charge, q = -1

As we know the valance electron of Be is +2 and the valance electron of bromine is -1. Since one is metallic and the other is non-metallic.

Now, when they combine they exchange valance electron, and bromine change into bromide so they form Beryllium Bromide.

So, the best name for the ionic bond that forms between them is Beryllium Bromide.

Learn more about ionic bonds here:

brainly.com/question/21464719

#SPJ4

8 0

2 years ago

A van accelerates from 4m/s to 20m/s in 8s. How far does it travel in this time?

zubka84 [21]

Answer:

96 m

Explanation:

Given,

Initial velocity ( u ) = 4 m/s

Final velocity ( v ) = 20 m/s

Time ( t ) = 8 s

Let Acceleration be " a ".

Formula : -

a = ( v - u ) / t

a = ( 20 - 4 ) / 8

= 16 / 8

a = 2 m/s²

Let displacement be " s ".

Formula : -

s = ut + at² / 2

s = ( 4 ) ( 8 ) + ( 2 ) ( 8² ) / 2

= 32 + ( 2 ) ( 64 ) / 2

= 32 + ( 2 ) ( 32 )

= 32 + 64

s = 96 m

Therefore, it travels 96 m in time 8 s.

3 0

3 years ago

Say that you are in a large room at temperature TC = 300 K. Someone gives you a pot of hot soup at a temperature of TH = 340 K.

DiKsa [7]

Answer:0.061

Explanation:

Given

$T_C=300 k$

Temperature of soup $T_H=340 K$

heat capacity of soup $c_v=33 J/K$

Here Temperature of soup is constantly decreasing

suppose T is the temperature of soup at any instant

efficiency is given by

$\eta =\frac{dW}{Q}=1-\frac{T_C}{T}$

$dW=Q(1-\frac{T_C}{T})$

$dW=c_v(1-\frac{T_C}{T})dT$

integrating From $T_H$ to $T_C$

$\int dW=\int_{T_C}^{T_H}c_v(1-\frac{T_C}{T})dT$

$W=\int_{T_C}^{T_H}33\cdot (1-\frac{300}{T})dT$

$W=c_v\left [ T-T_C\ln T\right ]_{T_H}^{T_C}$

$W=c_v\left [ \left ( T_C-T_H\right )-T_C\left ( \ln \frac{T_C}{T_H}\right )\right ]$

Now heat lost by soup is given by

$Q=c_v(T_C-T_H)$

Fraction of the total heat that is lost by the soup can be turned is given by

$=\frac{W}{Q}$

$=\frac{c_v\left [ \left ( T_C-T_H\right )-T_C\left ( \ln \frac{T_C}{T_H}\right )\right ]}{c_v(T_C-T_H)}$

$=\frac{T_C-T_H-T_C\ln (\frac{T_C}{T_H})}{T_C-T_H}$

$=\frac{300-340-300\ln (\frac{300}{340})}{300-340}$

$=\frac{-40+37.548}{-40}$

$=0.061$

4 0

2 years ago

The average speed of an object which moves 100 m in 5 seconds is?

CaHeK987 [17]

Answer:

A car

Explanation:

A car can travel 100 m in 5 seconds

Hope this helps!

3 0

3 years ago