All categories

3 years ago

6. An object accelerates from rest to 70 m/s in 3.5 s. What is the acceleration of the object?

Physics

1 answer:

sweet-ann [11.9K]3 years ago

4 0

Answer:

The acceleration of the object is 20 meters per second square = 20 m/s^2

Explanation:

Recall that acceleration is defined as the change in velocity divided the time it takes for the change. Therefore , if the object accelerates from rest (zero velocity) to 70 m/s , the change in velocity is (70 m/s - 0 m/s = 70 m/s)

which divided by the 3.5 seconds it took for the change, gives:

acceleration = (70 m/s / 3.5 s ) = 20 m/s^2

You might be interested in

There are two different alleles for the number of fingers on the hands: 5 finger allele and 6 finger allele. When both the 5 fin

padilas [110]

Answer:

The 6 fingers allele is dominant

Explanation:

We are told that the the individual is genotypically heterozygous, that is the have both types of the finger allele: the 5 finger allele and the 6 fingers allele however phenotypically, 6 fingers are observed. From this we can conclude that the 6 fingers allele is the one that is dominant because it is the one that is expressed phenotypically.

8 0

3 years ago

A kettle is rated at 1 kW, 220 V. Calculate the working resistance of the kettle.

Anna [14]

Explanation:

Power of electric kettle, P = 1 kW

Voltage, V = 220 V

(a) Electric power is given by the formula as follows :

$P=\dfrac{V^2}{R}$

R is resistance

$R=\dfrac{V^2}{P}\\\\R=\dfrac{(220)^2}{10^3}\\\\R=48.4\ \Omega$

(b) When connected to a 220 V supply, it takes 3 minutes for the water in the kettle to reach boiling point.

Energy supplied is given by :

$E=P\times t$

P is power, $P=\dfrac{V^2}{R}$

$E=\dfrac{V^2}{R}t\\\\E=\dfrac{(220)^2}{48.4}\times 180\\\\E=180000\ J\\\\E=180\ kJ$

5 0

3 years ago

A book on a 2-meter high shelf has a mass of 0.4 kg. What is its potential energy?

poizon [28]

Answer:

$\boxed {\boxed {\sf 7.84 \ Joules}}$

Explanation:

The formula for potential energy is:

$PE=m*g*h$

where m is the mass, g is the gravitational acceleration, and h is the height.

The mass of the book is 0.4 kilograms. The gravitational acceleration on Earth is 9.8 m/s². The height of the book is 2 meters.

$m=0.4 \ kg \\g=9.8 \ m/s^2 \\h=2\ m$

Substitute the values into the formula.

$PE=(0.4 \ kg)(9.8 \ m/s^2)(2 \ m)$

Multiply the first two numbers.

0.4 kg*9.8 m/s²= 3.92 kg*m/s²
If we convert the units now, the problem will be much easier later on.
1 kg*m/s² is equal to 1 Newton. So, our answer of 3.92 kg*m/s² is equal to 3.92 N

$PE=(3.92 \ N )(2 \ m)$

Multiply.

3.92 N* 2 m=7.84 N*m
1 Newton meter is equal to 1 Joule (this is why we converted the units).
Our answer is equal to 7.84 Joules.

$PE=7.84 \ J$

6 0

2 years ago

Read 2 more answers

A rocket will move upward as long as which condition applies?

Dennis_Churaev [7]

The force of thrust is greater than the force if gravity !
Answer found on quizlet !

8 0

3 years ago

Danny lowers the sails on his boat. He paddles upstream at 19 km/hr. The current is still running downstream at 15 km/hr. What i

Molodets [167]

Answer:

4 km/hr

Explanation:

The computation of the actual velocity is shown below:

Because the path of its paddles is opposed to the current direction, the real velocity can be determined by deducting the current velocity to its velocity while paddling

So, the actual velocity is

= Upstream - downstream

= 19 km/hr - 15 km/hr

= 4 km/hr

As we can see it is in positive, so it is an upstream direction

3 0

3 years ago